Fitting potential energy and induced dipole surfaces of the van der Waals complex CH<sub>4</sub>–N<sub>2</sub> using non-product quadrature grids
Artem A. Finenko, Daniil N. Chistikov, Yulia N. Kalugina, E. K. Conway, Iouli E. Gordon
Abstract
, respectively. One can take advantage of the symmetry when fitting the surfaces; first, when constructing angular basis functions and second, when selecting the grid points. The approach to the construction of scalar and vectorial basis functions exploiting the eigenfunction method [Q. Chen, J. Ping and F. Wang, Group Representation Theory for Physicists, World Scientific, 2nd edn, 2002] is developed. We explore the use of Sobolev-type quadrature grids as building blocks of robust quadrature rules adapted to the symmetry of the molecular system. Temperature variations of the cross second virial coefficient and first classical spectral moments of the rototranslational collision-induced band were derived. A reasonable agreement between calculated values and experimental data was found attesting to the high quality of constructed surfaces.