因为：
1 Bohr=0.52917721 Å
1 Hartree=27.2113845 eV
所以：
1.0 Hatree/(e Bohr)＝1.0*27.2113845eV/(e Bohr)=27.2113845/0.52917721 V/Å= 51.422 V/Å
