sanya
sanya@photonics.ru
Previously, we discussed thermochemistry, so I thought the question was about energy for thermochemistry. Of course, the energy of, say, single point calculation (without vibrations taken into account) corresponds to 0 K. To put it more precisely, this energy corresponds to a certain point lying exactly on the PES, i.e., to no temperature. After taking into account vibrations (for example, with RUNTYP=HESSIAN), ZPE correction gives the energy at 0 K, and including any nonzero temperature (by default, 298.15 K) gives the corresponding thermochemically relevant value.