Phosphorus mononitride: A difficult case for theory

0508902 - ÚOCHB 2020 RIV US eng J - Článek v odborném periodiku
Kupka, T. - Leszczyńska, M. - Ejsmont, K. - Mnich, A. - Broda, M. - Thangavel, Karthick - Kaminský, Jakub
Phosphorus mononitride: A difficult case for theory.
International Journal of Quantum Chemistry. Roč. 119, č. 24 (2019), č. článku e26032. ISSN 0020-7608. E-ISSN 1097-461X
Grant CEP: GA ČR(CZ) GA19-13436S
Institucionální podpora: RVO:61388963
Klíčová slova: NMR * Phosphorus nitride * PN * structure * vibrational frequency
Obor OECD: Physical chemistry
Impakt faktor: 1.747, rok: 2019
Způsob publikování: Omezený přístup
https://onlinelibrary.wiley.com/doi/abs/10.1002/qua.26032

Phosphorus nitride (PN) is the simplest molecule formed solely by phosphorus and nitrogen. It represents an interesting model for materials, where phosphorus is directly attached to nitrogen. Nevertheless, both theoretical and experimental studies often provide an incomplete picture on the structural, electronic, and spectral properties of PN. Theoretical predictions often suffer from insufficient level of theory, incomplete basis set, or from neglecting several effects, for example, zero-point vibrational correction (ZPVC). Therefore, we performed an extensive benchmark study on structural, electronic, and spectral properties of PN at the Hartree-Fock, density functional theory (DFT), or even the coupled-cluster levels. We paid special attention to the basis set effect. We tested three variants of Dunning's aug-cc-pVXZ basis sets with the size from double-zeta to sextuple-zeta, as well as Jensen's aug-pc-n, aug-pcJ-n, and aug-pcSseg-n basis sets, where n = 1-4. Obtained energetics, PN distance, dipole moment, vibrational frequencies, and nuclear magnetic resonance (NMR) parameters were extrapolated to the complete basis set limit (CBS) using three- or two-parameter formulas. The P-31 NMR shieldings estimated with the aug-cc-pVXZ and aug-cc-pV(X + d)Z basis sets strongly depend on the basis set size providing scattered convergence patterns toward CBS. The Hartree-Fock self-consistent field (HF-SCF) NMR parameters evinced similar behavior as the coupled-cluster data. The only smooth convergence was achieved using the aug-cc-pCVXZ basis sets that include core-valence effects. The KT3 functional underestimated the phosphorus CBS shieldings by about 12 ppm compared to coupled cluster with singles and doubles (CCSD) (T). Nevertheless, KT3 unambiguously surpasses the HF-SCF and CCSD levels that provide P-31 shieldings that are lower by about 150 ppm and 24 ppm compared to CCSD(T). The convergence of nitrogen shieldings was regular for all basis set hierarchies and all theoretical methods. Relativistic and vibrational effects on selected properties were also discussed.
Trvalý link: http://hdl.handle.net/11104/0299696