Investigating the accuracy of density functional methods for molecules in electric fields

Abstract

The use of oriented external electric fields (OEEFs) as a potential tool for catalyzing chemical reactions has gained traction in recent years. Electronic structure calculations using OEEFs are commonly done using methods based on density functional theory (DFT), but until now, the performance of DFT methods for calculating molecules in OEEFs had not been assessed in a more general scope. Looking at the accuracy of molecular geometries, electronic energies, and electric dipole moments compared to accurate coupled-cluster with perturbative triples data, we have investigated a wide variety of density functionals using different basis sets to determine how well the individual functionals perform on various types of chemical bonds. We found that most functionals accurately calculate geometries in OEEFs and that small basis sets are sufficient in many cases. Calculations of electronic energies show a significant error introduced by the OEEF, which the use of a larger basis set helps mitigate. Our findings show that DFT methods can be used for accurate calculations in OEEFs, allowing researchers to make full use of the advantages that they bring.

On the Interplay Between Force, Temperature, and Electric Fields in the Rupture Process of Mechanophores

“…Electronic structure calculations were performed using Q-Chem 6.1.1 35 at the ωB97X-V/cc-pVDZ level of theory, 36,37 which has been shown to provide good accuracy when simulating organic molecules in strong electric fields. 38 We investigated the influence of an OEEF on the scissile bond under thermal conditions. To achieve this, we performed single-molecule Born-Oppenheimer Molecular Dynamics (BOMD) simulations.…”

Using oriented external electric fields to manipulate rupture forces of mechanophores

“…41 All electronic structure calculations were performed at the oB97X-V/cc-pVDZ level of theory, 42,43 which has been shown to provide good accuracy when calculating organic molecules in strong electric fields. 44 We investigated the rupture force of each structure's scissile bond depending on the electric field strength. Electric fields were applied along the stretching coordinate indicated by arrows in Fig.…”

“…41 All electronic structure calculations were performed at the ωB97X-V/cc-pVDZ level of theory, 42,43 which has been shown to provide good accuracy when calculating organic molecules in strong electric fields. 44…”

Water Dimer under Electric Fields: An Ab Initio Investigation up to Quantum Accuracy

“…The spectroscopic response of single-molecule and bulk liquid , water systems has been thoroughly investigated by means of density functional theory (DFT) approaches in the context of vibrational Stark spectroscopy, in which frequency shifts induced by intense EFs to selected vibrational modes are conveniently exploited as local probes . An impressive recent study has explored the accuracy of several DFT methods for simple (a)­polar molecules placed under external intense EFs. Although density functionals usually employed for identifying molecular geometries or electronic energies are known to suffer from the delocalization erroralso when molecules are exposed to EFs − Scheele and Neudecker show that “DFT methods can be used for accurate calculations in oriented external electric fields”.…”

“…An impressive recent study has explored the accuracy of several DFT methods for simple (a)­polar molecules placed under external intense EFs. Although density functionals usually employed for identifying molecular geometries or electronic energies are known to suffer from the delocalization erroralso when molecules are exposed to EFs − Scheele and Neudecker show that “DFT methods can be used for accurate calculations in oriented external electric fields”. However, neither the water monomer nor any dimer was included in the latter investigation.…”