Get and run OpenRSP
If you want to get OpenRSP and use it for calculations, then please make note of the following: OpenRSP is a program library that manages the calculation of response properties, and it cannot calculate these properties without getting contributions like perturbed one- and two-electron integrals or solutions of response equations from other codes to which it connects through the application programming interface (API). This means that if you download and build OpenRSP from its GitHub repository, the compiled product will not on its own be able to calculate response properties. A set of API connections to enable OpenRSP to manage response property calculations can for example be made in quantum chemistry programs the where necessary routines for these contributions are implemented.
Consequently, in order to use OpenRSP for calculations, it is necessary to use it in a host program into which OpenRSP has been incorporated in this way, and a list of such programs is kept at the :ref:`chapter_programs_with_openrsp` page. The specific way in which OpenRSP is invoked in a host program - i.e. the way that you can make OpenRSP calculate something in that program - is a feature of each such program, and you must therefore follow the relevant instructions to achieve this, as may for example be shown in the user manual for the host program that you want to use.