@article{kulahlioglu_mitas_2019, title={A quantum Monte Carlo study of the molybdenum dimer (Mo-2)}, volume={1170}, ISSN={["1872-7999"]}, DOI={10.1016/j.comptc.2019.112642}, abstractNote={We have studied the molybdenum dimer (Mo2) system. The binding energy was calculated by means of the fixed-node DMC (FN-DMC) method. The Slater part of the trial wave function was constructed by the Selected-CI method by using the orbitals generated by the KS-DFT method with a hybrid meta-GGA exchange and correlation functional, TPSSh. We also carried out CCSD(T) calculations which were subsequently extrapolated to the complete basis set (CBS) limit. The results are presented.}, journal={COMPUTATIONAL AND THEORETICAL CHEMISTRY}, author={Kulahlioglu, Adem Halil and Mitas, Lubos}, year={2019}, month={Dec} }
@article{bennett_kulahlioglu_mitas_2017, title={A quantum Monte Carlo study of mono(benzene) TM and bis(benzene) TM systems}, volume={667}, ISSN={["1873-4448"]}, DOI={10.1016/j.cplett.2016.11.032}, abstractNote={We present a study of mono(benzene)TM and bis(benzene)TM systems, where TM={Mo,W}. We calculate the binding energies by quantum Monte Carlo (QMC) approaches and compare the results with other methods and available experiments. The orbitals for the determinantal part of each trial wave function were generated from several types of DFT in order to optimize for fixed-node errors. We estimate and compare the size of the fixed-node errors for both the Mo and W systems with regard to the electron density and degree of localization in these systems. For the W systems we provide benchmarking results of the binding energies, given that experimental data is not available.}, journal={CHEMICAL PHYSICS LETTERS}, author={Bennett, M. Chandler and Kulahlioglu, A. H. and Mitas, L.}, year={2017}, month={Jan}, pages={74–78} }
@article{kulahlioglu_mitas_2014, title={A quantum Monte Carlo study of zinc-porphyrin: Vertical excitation between the singlet ground state and the lowest-lying singlet excited state}, volume={1046}, ISSN={2210-271X}, url={http://dx.doi.org/10.1016/J.COMPTC.2014.07.006}, DOI={10.1016/j.comptc.2014.07.006}, abstractNote={We have calculated the vertical excitation energy between the singlet ground state (11Ag) and the lowest-lying singlet excited state (11Eu) of Zn-porphyrin employing the fixed-node diffusion Monte Carlo technique. The determinantal parts of trial wave functions were constructed using results from Configuration Interaction and time-dependent Density Functional Theory.}, journal={Computational and Theoretical Chemistry}, publisher={Elsevier BV}, author={Kulahlioglu, A.H. and Mitas, L.}, year={2014}, month={Oct}, pages={6–9} }
@article{kulahlioglu_rasch_hu_mitas_2014, title={Density dependence of fixed-node errors in diffusion quantum Monte Carlo: Triplet pair correlations}, volume={591}, ISSN={["1873-4448"]}, DOI={10.1016/j.cplett.2013.11.033}, abstractNote={Abstract We analyze trial wave function fixed-node errors for a three-electron fully spin-polarized atomic systems with varying atomic number Z . The fully spin-polarized state 4 S ( 1 s 2 s 3 s ) is the lowest quadruplet with S -symmetry and even parity and it is nearly-degenerate with the 4 S ( 1 s 2 p 3 p ) state. We find significant fixed-node errors proportional to Z at the Hartree–Fock level while the two-configuration wave function leads to nearly exact energies. This broadly agrees with our analogous study on Be-like atoms so that the dependence of fixed-node errors on density appears to be similar in both spin-polarized and unpolarized atomic systems.}, journal={CHEMICAL PHYSICS LETTERS}, author={Kulahlioglu, Adem H. and Rasch, Kevin and Hu, Shuming and Mitas, Lubos}, year={2014}, month={Jan}, pages={170–174} }