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Fundamental and Computational Sciences Directorate

Staff information

Karol Kowalski

Interfacial Sciences & Simulation
Pacific Northwest National Laboratory
PO Box 999
MSIN: K8-91
Richland, WA 99352

PNNL Publications


  • Berardo E, F Kaplan, K Bhaskaran Nair, WA Shelton, MJ Van Setten, K Kowalski, and MA Zwijnenburg. 2017. "Benchmarking the Fundamental Electronic Properties of small TiO2 Nanoclusters by GW and Coupled Cluster Theory Calculations." Journal of Chemical Theory and Computation 13(8):3470-3477.  doi:10.1021/acs.jctc.7b00538
  • Moore B, R Schrader, K Kowalski, and J Autschbach. 2017. "Electronic pi to pi* excitations of rhodamine dyes exhibit a time-dependent Kohn-Sham theory "cyanine problem"." ChemistryOPEN 6(3):385-392.  doi:10.1002/open.201700046
  • Peng B, N Govind, E Apra, M Klemm, JR Hammond, and K Kowalski. 2017. "Coupled Cluster Studies of Ionization Potentials and Electron Affinities of Single-Walled Carbon Nanotubes." Journal of Physical Chemistry A 121(6):1328-1335.  doi:10.1021/acs.jpca.6b10874
  • Peng B, and K Kowalski. 2017. "Low-rank factorization of electron integral tensors and its application in electronic structure theory." Chemical Physics Letters 672:47-53.  doi:10.1016/j.cplett.2017.01.056
  • Pirojsirikul T, AW Goetz, JH Weare, RC Walker, K Kowalski, and M Valiev. 2017. "Combined Quantum-Mechanical Molecular Mechanics Calculations with NWChem and AMBER: Excited State Properties of Green Fluorescent Protein Chromophore Analogue in Aqueous Solution." Journal of Computational Chemistry 38(18):1631-1639.  doi:10.1002/jcc.24804


  • Bhaskaran-Nair K, K Kowalski, and WA Shelton, JR. 2016. "Coupled Cluster Green function: model involving single and double excitations." Journal of Chemical Physics 144(14):144101.  doi:10.1063/1.4944960
  • Brabec J, S Banik, K Kowalski, and J Pittner. 2016. "Perturbative universal state-selective correction for a state-specific multi-reference coupled cluster methods." Journal of Chemical Physics 145(16):Article No. 164106.  doi:10.1063/1.4965826
  • Hu H, YF Zhao, JR Hammond, EJ Bylaska, E Apra, HJJ van Dam, J Li, N Govind, and K Kowalski. 2016. "Theoretical studies of the global minima and polarizabilities of small lithium clusters." Chemical Physics Letters 644:235-242.  doi:10.1016/j.cplett.2015.11.049
  • Ma X, RW Hall, F Loffler, K Kowalski, K Bhaskaran-Nair, M Jarrell, and J Moreno. 2016. "Sign learning kink-based (SiLK) quantum Monte Carlo for molecular systems." Journal of Chemical Physics 144(1):Article No. 014101.  doi:10.1063/1.4939145
  • Peng B, and K Kowalski. 2016. "Coupled-cluster Green’s function: analysis of properties originating in the exponential parametrization of the ground-state wave function." Physical Review. A. 94(6):Article No. 062512.  doi:10.1103/PhysRevA.94.062512


  • Apra E, K Kowalski, JR Hammond, and M Klemm. 2015. "NWChem: Quantum Chemistry Simulations at Scale." Chapter 17 in High Performance Parallelism Pearls - Multicore and Many-core Programming Approaches, pp. 287-306.  Morgan Kaufmann, Waltham, MA. 
  • Banik S, L Ravichandran, J Brabec, I Hubac, K Kowalski, and J Pittner. 2015. "Iterative universal state selective correction for the Brillouin-Wigner multireference coupled-cluster theory." Journal of Chemical Physics 142(15):Article No. 114106.  doi:10.1063/1.4914311
  • Bhaskaran-Nair K, K Kowalski, M Jarrell, J Moreno, and WA Shelton. 2015. "Equation of motion coupled cluster methods for electron attachment and ionization potential in polyacenes." Chemical Physics Letters 641:146-152.  doi:10.1016/j.cplett.2015.10.071
  • Bhaskaran-Nair K, M Valiev, S Deng, WA Shelton, JR, K Kowalski, and XB Wang. 2015. "Probing microhydration effect on the electronic structure of the GFP chromophore anion: Photoelectron spectroscopy and theoretical investigations." Journal of Chemical Physics 143(22):Article No. 224301. 
  • Moore B, H Sun, N Govind, K Kowalski, and J Autschbach. 2015. "Charge-Transfer Versus Charge-Transfer-Like Excitations Revisited." Journal of Chemical Theory and Computation 11(7):3305-3320.  doi:10.1021/acs.jctc.5b00335


  • Kowalski K, K Bhaskaran-Nair, and WA Shelton. 2014. "Coupled-cluster representation of Green function employing modified spectral resolutions of similarity transformed Hamiltonians." Journal of Chemical Physics 141(9):Article No. 094102.  doi:10.1063/1.4893527
  • Anisimov V, GH Bauer, K Chadalavada, RM Olson, JW Glenski, WT Kramer, E Apra, and K Kowalski. 2014. "Optimization of the Coupled Cluster Implementation in NWChem on Petascale Parallel Architectures." Journal of Chemical Theory and Computation 10(10):4307-4316.  doi:10.1021/ct500404c
  • Apra E, M Klemm, and K Kowalski. 2014. "Efficient Implementation of Many-body Quantum Chemical Methods on the Intel Xeon Phi Coprocessor." In International Conference for High Performance Computing, Networking, Storage and Analysis (SC14), November 16-21, 2014, New Orleans, Louisiana, pp. 674-684.  IEEE , Piscataway, NJ.  doi:10.1109/SC.2014.60
  • Berardo E, H Hu, HJJ van Dam, SA Shevlin, SM Woodley, K Kowalski, and MA Zwijnenburg. 2014. "Describing excited state relaxation and localization in TiO2 nanoparticles using TD-DFT." Journal of Chemical Theory and Computation 10(12):5538-5548.  doi:10.1021/ct500787x
  • Berardo E, H Hu, SA Shevlin, SM Woodley, K Kowalski, and MA Zwijnenburg. 2014. "Modeling Excited States in TiO2 Nanoparticles: On the Accuracy of a TD-DFT Based Description." Journal of Chemical Theory and Computation 10(3):1189-1199.  doi:10.1021/ct4010273
  • Bhaskaran-Nair K, K Kowalski, J Moreno, M Jarrell, and WA Shelton. 2014. "Equation of motion coupled cluster methods for electron attachment and ionization potential in fullerenes C60 and C70." Journal of Chemical Physics 141(7):Article No. 074304.  doi:10.1063/1.4891934
  • Hu H, K Bhaskaran-Nair, E Apra, N Govind, and K Kowalski. 2014. "Toward enabling large-scale open-shell equation-of-motion coupled cluster calculations: triplet states of ß-carotene." Journal of Physical Chemistry A 118(39):9087-9093.  doi:10.1021/jp5021214
  • Pederzoli M, L Sobek, J Brabec, K Kowalski, L Cwiklik, and J Pittner. 2014. "Fluorescence of PRODAN in Water: a Computational QM/MM MD Study." Chemical Physics Letters 597:57-62.  doi:10.1016/j.cplett.2014.02.031


  • Berardo E, H Hu, K Kowalski, and MA Zwijnenburg. 2013. "Coupled cluster calculations on TiO2 nanoclusters." Journal of Chemical Physics 139(6):Article No. 064313.  doi:10.1063/1.4817536
  • Bhaskaran-Nair K, and K Kowalski. 2013. "Bridging single and multireference coupled cluster theories with universal state selective formalism." Journal of Chemical Physics 138(20):Article No. 204114.  doi:10.1063/1.4806768
  • Bhaskaran-Nair K, W Ma, S Krishnamoorthy, O Villa, HJJ van Dam, E Apra, and K Kowalski. 2013. "Noniterative Multireference Coupled Cluster Methods on Heterogeneous CPU-GPU Systems." Journal of Chemical Theory and Computation 9(4):1949-1957. 
  • Hu H, and K Kowalski. 2013. "Excitation energies with cost-reduced variant of the active-space EOMCCSDT method: the EOMCCSDt-(3) over-bar approach." Journal of Chemical Theory and Computation 9(11):4761-4768.  doi:10.1021/ct400501z
  • Ma W, S Krishnamoorthy, O Villa, K Kowalski, and G Agrawal. 2013. "Optimizing Tensor Contraction Expressions for Hybrid CPU-GPU Execution." Cluster Computing 16(1):131-155.  doi:10.1007/s10586-011-0179-2
  • Tecmer P, N Govind, K Kowalski, WA De Jong, and L Visscher. 2013. "Reliable Modeling of the Electronic Spectra of Realistic Uranium Complexes." Journal of Chemical Physics 139(3):Article No. 034301.  doi:10.1063/1.4812360


  • Bhaskaran-Nair K, and K Kowalski. 2012. "Note: Excited State Studies of Ozone using State-Specific Multireference Coupled Cluster Methods." Journal of Chemical Physics 137(21):Article No. 216101.  doi:10.1063/1.4769775
  • Bhaskaran-Nair K, J Brabec, E Apra, HJJ van Dam, J Pittner, and K Kowalski. 2012. "Implementation of the multireference Brillouin-Wigner and Mukherjee’s coupled cluster methods with non-iterative triple excitations utilizing reference-level parallelism." Journal of Chemical Physics 137(9):094112-1 to 094112-12.  doi:10.1063/1.4747698
  • Brabec J, HJJ van Dam, J Pittner, and K Kowalski. 2012. "Universal state-selective corrections to multireference coupled-cluster theories with single and double excitations." Journal of Chemical Physics 136(12):Article No. 124102.  doi:10.1063/1.3692969
  • Brabec J, J Pittner, HJJ van Dam, E Apra, and K Kowalski. 2012. "Parallel implementation of multireference coupled-cluster theories based on the reference-level parallelism." Journal of Chemical Theory and Computation 8(2):487-497. 
  • Brabec J, K Bhaskaran-Nair, K Kowalski, J Pittner, and HJJ van Dam. 2012. "Towards large-scale calculations with State-Specific Multireference Coupled Cluster methods: Studies on dodecane, naphthynes, and polycarbenes." Chemical Physics Letters 542:128-133.  doi:10.1016/j.cplett.2012.05.064
  • Brabec J, K Bhaskaran-Nair, N Govind, J Pittner, and K Kowalski. 2012. "Communication: Application of state-specific multireference coupled cluster methods to core-level excitations." Journal of Chemical Physics 137(17):Article No.171101.  doi:10.1063/1.4764355
  • Hou G, H Wen, KA Lopata, W Zheng, K Kowalski, N Govind, XB Wang, and SS Xantheas. 2012. "A Combined Gas-Phase Photoelectron Spectroscopic and Theoretical Study of Zeise's Anion and Its Bromine and Iodine Analogues." Angewandte Chemie International Edition 51(26):6356-6360.  doi:10.1002/anie.201201959


  • Kowalski K, RM Olson, S Krishnamoorthy, V Tipparaju, and E Apra. 2011. "Role of Many-Body Effects in Describing Low-Lying Excited States of pi-Conjugated Chromophores: High-Level Equation-of-Motion Coupled-Cluster Studies of Fused Porphyrin Systems." Journal of Chemical Theory and Computation 7(7):2200-2208.  doi:10.1021/ct200217y
  • Kowalski K, S Krishnamoorthy, RM Olson, V Tipparaju, and E Apra. 2011. "Scalable implementations of accurate excited-state coupled cluster theories: application of high-level methods to porphyrin based systems." In Proceedings of International Conference for High Performance Computing, Networking, Storage and Analysis (SC'11), November 12-18, 2011, Seattle, Washington, p. Article No. 72.  Association for Computing Machinery, New York, NY.  doi:10.1145/2063384.2063481
  • Kowalski K. 2011. "A universal state-selective approach to multireference coupled-cluster non-iterative corrections." Journal of Chemical Physics 134(19):Article No. 194107.  doi:10.1063/1.3589896
  • Ali N, S Krishnamoorthy, N Govind, K Kowalski, and P Sadayappan. 2011. "Application-Specific Fault Tolerance via Data Access Characterization." In Proceedings of the 17th International European Conference on Parallel and Distributed Computing, (Euro-Par 2011), August 29-September 2, 2011, Bordeaux, France. Lecture Notes in Computer Science, vol. 6853, ed. E Jeannot, R Namyst and J Roman, pp. 340-352.  Springer-Verlag, Berlin, Germany.  doi:10.1007/978-3-642-23397-5
  • Brabec J, S Krishnamoorthy, HJJ van Dam, K Kowalski, and J Pittner. 2011. "Massively parallel implementation of the multi-reference Brillouin-Wigner CCSD method." Chemical Physics Letters 514(4-6):347-351.  doi:10.1016/j.cplett.2011.08.016
  • Campbell CT, AK Datye, GA Henkelman, RF Lobo, WF Schneider, LD Spicer, WT Tysoe, JM Vohs, DR Baer, DW Hoyt, S Thevuthasan, KT Mueller, CM Wang, NM Washton, I Lyubinetsky, RG Teller, A Andersen, N Govind, K Kowalski, BC Kabius, H Wang, AA Campbell, WA Shelton, EJ Bylaska, CHF Peden, Y Wang, DL King, MA Henderson, RJ Rousseau, J Szanyi, Z Dohnalek, D Mei, BC Garrett, D Ray, JH Futrell, J Laskin, DL DuBois, LR Kuprat, and C Plata. 2011. EMSL and Institute for Integrated Catalysis (IIC) Catalysis WorkshopPNNL-20426, Pacific Northwest National Laboratory, Richland, WA. 
  • Govind N, EJ Bylaska, WA De Jong, K Kowalski, TP Straatsma, M Valiev, and HJJ van Dam. 2011. "NWChem." In Encyclopedia of Parallel Computing, ed. D Padua, pp. 1345-1353.  Springer, New York, NY. 
  • Govind N, KA Lopata, RJ Rousseau, A Andersen, and K Kowalski. 2011. "Visible Light Absorption of N-Doped TiO2 Rutile Using (LR/RT)-TDDFT and Active Space EOMCCSD Calculations." The Journal of Physical Chemistry Letters 2(21):2696-2701.  doi:10.1021/jz201118r
  • Lopata KA, R Reslan, MI Kowalska, D Neuhauser, N Govind, and K Kowalski. 2011. "Excited-state studies of polyacenes: A comparative picture using EOMCCSD, CR-EOMCCSD(T), range-separated (LR/RT)-TDDFT, TD-PM3 and TD-ZINDO." Journal of Chemical Theory and Computation 7(11):3686-3693. 
  • Ma W, S Krishnamoorthy, O Villa, and K Kowalski. 2011. "GPU-based implementations of the noniterative regularized-CCSD(T) corrections: applications to strongly correlated systems." Journal of Chemical Theory and Computation 7(5):1316-1328.  doi:10.1021/ct1007247
  • van Dam HJJ, WA De Jong, EJ Bylaska, N Govind, K Kowalski, TP Straatsma, and M Valiev. 2011. "NWChem: scalable parallel computational chemistry." Wiley Interdisciplinary Reviews: Computational Molecular Science 1(6):888-894.  doi:10.1002/wcms.62


  • De Jong WA, EJ Bylaska, N Govind, CL Janssen, K Kowalski, T Muller, I Nielsen, HJJ van Dam, VV Veryazov, and R Lindh. 2010. "Utilizing High Performance Computing for Chemistry: Parallel Computational Chemistry." Physical Chemistry Chemical Physics. PCCP 12(26):6896-6920. 
  • Glaesemann KR, N Govind, S Krishnamoorthy, and K Kowalski. 2010. "EOMCC, MRPT, and TDDFT Studies of Charge Transfer Processes in Mixed-Valence Compounds: Application to the Spiro Molecule ." Journal of Physical Chemistry A 114(33):8764-8771.  doi:10.1021/jp101761d
  • Govind N, RJ Rousseau, A Andersen, and K Kowalski. 2010. "Visible-Light Photoresponse of Nitrogen-Doped TiO2: Excited State Studies using Time-Dependent Density Functional Theory and Equation-of-Motion Coupled Cluster Methods." In Materials Research Society Symposium Proceedings, Symposium Y: Computational Approaches to Materials for Energy, vol. 1263, pp. Paper No. 1263-Y04-06.  Materials Research Society, Warrendale, PA.  doi:10.1557/PROC-1263-Y04-06
  • Kowalski K, S Krishnamoorthy, O Villa, JR Hammond, and N Govind. 2010. "Active-space completely-renormalized equation-of-motion coupled-cluster formalism: Excited-state studies of green fluorescent protein, free-base porphyrin, and oligoporphyrin dimer ." Journal of Chemical Physics 132(15):Article Number: 154103. 
  • Ma W, S Krishnamoorthy, O Villa, and K Kowalski. 2010. "Acceleration of Streamed Tensor Contraction Expressions on GPGPU-based Clusters." In Proceedings of the IEEE International Conference on Cluster Computing (CLUSTER 2010), pp. 207-216.  Institute of Electrical and Electronic Engineers, Piscataway, NJ.  doi:10.1109/CLUSTER.2010.26
  • Valiev M, EJ Bylaska, N Govind, K Kowalski, TP Straatsma, HJJ van Dam, D Wang, J Nieplocha, E Apra, TL Windus, and WA De Jong. 2010. "NWChem: a Comprehensive and Scalable Open-Source Solution for Large Scale Molecular Simulations." Computer Physics Communications 181(9):1477-1489.  doi:10.1016/j.cpc.2010.04.018
  • Wang XB, K Kowalski, LS Wang, and SS Xantheas. 2010. "Stepwise hydration of the cyanide anion: A temperature-controlled photoelectron spectroscopy and ab initio computational study of CN-(H2O)n(n=2-5)." Journal of Chemical Physics 132(12):124306/1-10.  doi:10.1063/1.3360306


  • Govind N, M Valiev, L Jensen, and K Kowalski. 2009. "Excitation Energies of Zinc Porphyrin in Aqueous Solution Using Long-Range Corrected Time-Dependent Density Functional Theory." Journal of Physical Chemistry A 113(21):6041-6043.  doi:10.1021/jp902118k
  • Govind N, PV Sushko, WP Hess, M Valiev, and K Kowalski. 2009. "Excitons in Potassium Bromide: A Study using Embedded Time-dependent Density Functional Theory and Equation-of-Motion Coupled Cluster Methods." Chemical Physics Letters 470(4-6):353-357.  doi:10.1016/j.cplett.2009.01.073
  • Kowalski K. 2009. "Nested Variant of the Method of Moments of Coupled Cluster Equations for Vertical Excitation Energies and Excited-state Potential Energy Surfaces." Journal of Chemical Physics 130(19):Art. No. 194110. 
  • Hammond JR, N Govind, K Kowalski, J Autschbach, and SS Xantheas. 2009. "Accurate dipole polarizabilities for water clusters n=2-12 at the coupled-cluster level of theory and benchmarking of various density functionals." Journal of Chemical Physics 131(21):Article Number:214103. 
  • Hammond JR, and K Kowalski. 2009. "Parallel Computation of Coupled Cluster Hyperpolarizabilities." Journal of Chemical Physics 130(19):Art. No. 194108. 
  • Kowalski K, and M Valiev. 2009. "Extensive regularization of the coupled cluster methods based on the generating functional formalism: application to gas-phase benchmarks and to the S(N)2 reaction of CHCl3 and OH- in water." Journal of Chemical Physics 131(23):Article Number 234107. 
  • Kowalski K, and PD Fan. 2009. "Generating Functionals Based Formulation of the Method of Moments of Coupled Cluster Equations." Journal of Chemical Physics 130(8):Art No. 084112. 
  • Wang XB, JC Werhahn, LS Wang, K Kowalski, A Laubereau, and SS Xantheas. 2009. "Observation of a remarkable temperature effect in the hydrogen bonding structure and dynamics of the CN-(H2O) cluster." Journal of Physical Chemistry A 113(35):9579-9584. 


  • Fan PD, M Valiev, and K Kowalski. 2008. "Large-Scale Parallel Calculations with Combined Coupled Cluster and Molecular Mechanics Formalism: Excitation Energies of Zinc-porphyrin in Aqueous Solution." Chemical Physics Letters 458(1-3):205-209. 
  • Kowalski K, JR Hammond, WA De Jong, and AJ Sadlej. 2008. "Coupled Cluster Calculations for Static and Dynamic Polarizabilities of C60." Journal of Chemical Physics 129(22):226101.  doi:10.1063/1.3028541
  • Epifanovsky E, K Kowalski, PD Fan, M Valiev, S Matsika, and A Krylov. 2008. "On the Electronically Excited States of Uracil." Journal of Physical Chemistry A 112(40):9983-9992.  doi:10.1021/jp803758q
  • Hammond JR, WA De Jong, and K Kowalski. 2008. "Coupled-Cluster Dynamic Polarizabilities Including Triple Excitations." Journal of Chemical Physics 128:224102-1 - 224102-11.  doi:10.1063/1.2929840
  • Kowalski K, and M Valiev. 2008. "NonIterative Corrections to Equation-of-Motion Coupled-Cluster Excited State Energies Based on the Reduced Method of Moments of coupled cluster equation." International Journal of Quantum Chemistry 108(12):2178-2190.  doi:10.1002/qua.21741
  • Kowalski K, and M Valiev. 2008. "The Application of High-Level Iterative Coupled-Cluster Methods to the Cytosine Molecule." Journal of Physical Chemistry A 112(24):5538-5541. 


  • Kowalski K, JR Hammond, and WA De Jong. 2007. "Linear Response Coupled Cluster Singles and Doubles Approach with Modified Spectral Resolution of the Similarity Transformed Hamiltonian." Journal of Chemical Physics 127(16):164105 (9).  doi:10.1063/1.2795708
  • Valiev M, BC Garrett, MK Tsai, K Kowalski, SM Kathmann, GK Schenter, and M Dupuis. 2007. "Hybrid Approach for Free Energy Calculations with High-Level Methods: Application to the S(N)2 Reaction of CHCl3 and OH- in Water." Journal of Chemical Physics 127(5):51102 (1-4). 
  • Hammond JR, K Kowalski, and WA De Jong. 2007. "Dynamic Polarizabilities of Polyaromatic Hydrocarbons Using Coupled-Cluster Linear Response Theory." Journal of Chemical Physics 127:Art. No. 144105.  doi:10.1063/1.2772853
  • Hammond JR, M Valiev, WA De Jong, and K Kowalski. 2007. "Calculations of Molecular Properties in Hybrid Coupled-Cluster and Molecular Mechanics Approach." Journal of Physical Chemistry A 111(25):5492-5498.  doi:10.1021/jp070553x
  • Tsai MK, K Kowalski, M Valiev, and M Dupuis. 2007. "Signature OH Absorption Spectrum from cluster Models of Solvation: a solvent-to-solute charge transfer state." Journal of Physical Chemistry A 111(42):10478-10482.  doi:10.1021/jp074617f


  • Kowalski K, and WA De Jong. 2006. "Noniterative Inclusion of the Triply and Quadruply Excited Clusters: The Locally Renormalized Perspective." Journal of Molecular Structure - Theochem 768(1-3):45-52. 
  • Kowalski K. 2006. "Excitation Energies Through the Locally Renormalized Equation-of-Motion Formalism: Singles and Doubles Model." Journal of Chemical Physics 125(12):124101 (11 p.). 
  • Kowalski K. 2006. "Locally Renormalized Coupled-Cluster Equations for Singly and Doubly Excited Clusters." Molecular Physics 104(13-14):1989-1997.  doi:10.1080/00268970600668629
  • Valiev M, and K Kowalski. 2006. "Hybrid Coupled Cluster and Molecular Dynamics Approach: Application to the Excitation Spectrum of Cytosine in the Native DNA Environment." Journal of Chemical Physics 125(21):Art. No. 211101.  doi:10.1063/1.2403847
  • Dean DJ, M Hjorth-Jensen, K Kowalski, P Piecuch, and MW Wloch. 2006. "Coupled-Cluster Theory for Nuclei." Chapter 8 in Condensed Matter Theories, vol. 20, ed. John W. Clark, Robert M. Panoff, and Haochen Li, pp. 89-97.  Nova Publishers, Hauppauge, NY. 
  • Kowalski K, and M Valiev. 2006. "Asymptotic Extrapolation Scheme for Large-Scale Calculations with Hybrid Coupled Cluster and Molecular Dynamic Simulations." Journal of Physical Chemistry A 110(48):13106-13111. 
  • Kowalski K, and M Valiev. 2006. "Multiscale Dynamical Framework for High-Level Calculations of Finite Temperature Ground and Excited State Properties." In Journal of Physics: Conference Series ; SciDAC 2006, SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING, 25-29 June 2006, Denver, Colorado, USA , vol. 46, pp. 244-248.  Institute of Phyics Publishing, Philadelphia, PA.  doi:10.1088/1742-6596/46/1/035
  • Song J, E Apra, Y Khait, MR Hoffmann, and K Kowalski. 2006. "High-Level Ab-Initio Calculation on the NiO2 System." Chemical Physics Letters 428(4-6):277-282. 


  • Kowalski K, S Hirata, MW Wloch, P Piecuch, and TL Windus. 2005. "Active-Space Coupled-Cluster Study of Electronic States of Be3." Journal of Chemical Physics 123:074319 (6 pages). 
  • Kowalski K. 2005. "Completely Renormalized EOMCCSD(T) Method Employing Independent Optimization of the Cluster Product Terms." Chemical Physics Letters 411(4-6):306-310.  doi:10.1016/j.cplett.2005.06.024
  • Kowalski K. 2005. "Implementation of the Locally Renormalized CCSD (T) Approaches for Abitrary Reference Function ." Journal of Chemical Physics 123(1):014102 (9 pages). 
  • Piecuch P, S Hirata, K Kowalski, P Fan, and TL Windus. 2005. "Automated Derivation and Parallel Computer Implementation of Renormalized and Active-Space Coupled-Cluster Methods." International Journal of Quantum Chemistry 106(1):79-97. 

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