TY - JOUR

T1 - What Is More Important When Calculating the Thermodynamic Properties of Organic Crystals, Density Functional, Supercell, or Energy Second-Order Derivative Method Choice?

AU - Dubok, Aleksandr S

AU - Rychkov, Denis A

N1 - This work was supported by the RSF (Russian Science Foundation) project 23-73-10142 (https://rscf.ru/en/project/23-73-10142/) (accessed on 10 March 2025).

PY - 2025/3/16

Y1 - 2025/3/16

N2 - Calculation of second-order derivatives of energy using the DFT method is a valuable approach for the estimation of both the thermodynamical and mechanical properties of organic crystals from the first principles. This type of calculation requires specification of several computational parameters, including the functional, supercell, and method of phonon calculations. Nevertheless, the importance of these parameters is presented in the literature very modestly. In this work, we demonstrate the influence of these computational parameters on the accuracy of calculated second-order derivatives using the practical example of pyrazinamide polymorphs, including the plastically bending α form and the β, γ, and brittle δ form. The effects of the settings used on the resulting enthalpies of the polymorphic modifications of pyrazinamide are compared: supercell setting (primitive cell vs. appropriate supercell) has a much stronger impact than functional (PBE-D3BJ vs. Hamada rev-vdW-DF2) which in turn affects results significantly more than the method for second-order derivative computation (FD vs. DFPT approach). Finally, we propose some suggestions for choosing the right settings for calculating second-order derivatives for molecular crystals.

AB - Calculation of second-order derivatives of energy using the DFT method is a valuable approach for the estimation of both the thermodynamical and mechanical properties of organic crystals from the first principles. This type of calculation requires specification of several computational parameters, including the functional, supercell, and method of phonon calculations. Nevertheless, the importance of these parameters is presented in the literature very modestly. In this work, we demonstrate the influence of these computational parameters on the accuracy of calculated second-order derivatives using the practical example of pyrazinamide polymorphs, including the plastically bending α form and the β, γ, and brittle δ form. The effects of the settings used on the resulting enthalpies of the polymorphic modifications of pyrazinamide are compared: supercell setting (primitive cell vs. appropriate supercell) has a much stronger impact than functional (PBE-D3BJ vs. Hamada rev-vdW-DF2) which in turn affects results significantly more than the method for second-order derivative computation (FD vs. DFPT approach). Finally, we propose some suggestions for choosing the right settings for calculating second-order derivatives for molecular crystals.

KW - benchmarking

KW - dfpt

KW - dispersion correction

KW - energy second-order derivatives

KW - finite-difference approach

KW - functional choice

KW - polymorphism

KW - pyrazinamide

KW - supercell

KW - thermodynamic properties

UR - https://www.mdpi.com/2073-4352/15/3/274

UR - https://www.mendeley.com/catalogue/599816ef-5cf8-3ee7-99c1-5b09f4afda0f/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-105001431618&origin=inward&txGid=1bff50e734d7ff90244ea7efb7963900

U2 - 10.3390/cryst15030274

DO - 10.3390/cryst15030274

M3 - Article

VL - 15

JO - Crystals

JF - Crystals

SN - 2073-4352

IS - 3

M1 - 274

ER -