Quantum calculation on zero-point vibration energy of solid argon

Based on the first principles, using the many-body expansion theory and Hartree-Fock SCF method, we calculate the relations among the zero-point vibration energy and atomic displacement of deviating from the equilibrium position, vibration frequency, molar volume of fcc solid argon in the atomic distance of 2.3-4.0Å, then obtain the Gruneisen coefficient and the zero-point vibration pressure. It is included that the motion of atoms around equilibrium positions can be thought as approximate harmonic vibration. The larger the molar volume of solid argon is, the greater the vibration frequency and zero-point vibration energy are. With the increase of the molar volume, Gruneisen coefficient increase, while the zero-point vibration pressure decrease.