Libxc, however, does contain all the information necessary to perform the calculations (fraction of exact exchange, range separation parameter(s)).The same can be said about dispersion corrections: several functionals are available in Libxc that were parametrized with either semiclassical dispersion corrections à la Grimme, or various van der Waals functionals neither of these can be evaluated with the local density information provided to Libxc, and must be handled by the calling program. LDAs, GGAs, and meta-GGAs depend on local information, in the sense that the value of the density functional part of the energy density at a given point depends only on the values of the density, the gradient of the density, and the kinetic energy density and/or the density laplacian, respectively, at the given point:$$E^mathrm), dots].$$For these functionals, Libxc only handles the local part (as above) the evaluation of the exact exchange components must be done in the calling program. Bug reports and patches should be submitted over gitlab.To cite Libxc, the current reference isThe previous reference to the library wasIn Libxc you can find various types of functionals: LDA, GGA, and meta-GGA (mGGA) functionals. The original aim was to provide a portable, well tested and reliable set of these functionals to be used by all the codes of the European Theoretical Spectroscopy Facility (ETSF), but the library has since grown to be used in several other types of codes as well see below for a partial list.Libxc is written in C, but it also comes with Fortran and Python bindings. The original aim was to provide a portable, well tested and reliable set of these functionals to be used by all the codes of the European Theoretical Spectroscopy Facility (ETSF), but the library has since grown to be used in several other types of codes as well see below.Libxc is a library of exchange-correlation and kinetic energy functionals for density-functional theory. Libxc is a library of exchange-correlation and kinetic energy functionals for density-functional theory. Much of modern DFT re-search is devoted to developing such approximations, usually termed XC functionals. The quality of the results depends on the quality of this approximation. Exchange Correlation Functional In DftWhat Is Exchange Correlation FunctionalProximate a small (but vital) contribution, called the exchange-correlation (XC) energy.