Each isomer is a local minimum on the energy surface ( called the potential energy surface ) created from the total energy ( i.e. , the electronic energy , plus the repulsion energy between the nuclei ) as a function of the coordinates of all the nuclei .
Each isomer is a local minimum on the energy surface ( called the potential energy surface ) created from the total energy ( that is , the electronic energy , plus the repulsion energy between the nuclei ) as a function of the positions of all the nuclei .