Energy of Polyatomic Gas Formula

Equation for calculate energy of polyatomic gas is,

E = 3 × (n - 10) × R × T

where,
n = Number of atoms in a non-lenear molecule,
R = Gas Constant, (8.3144598(48) J×mol⁻¹×K⁻¹)
T = Temperature,
E = Average energy / mole