Pressure-Induced Restoration of the Reversed Crystal-Field Splitting in $alpha$-Sr$_2$CrO$_4$

Motivated by an experimental finding that the successive phase transitions in $alpha$-Sr$_2$CrO$_4$ observed at ambient pressure ceases to exist under high pressures, we carry out the density-functional-theory-based electronic structure calculations and demonstrate that the reversal of the crystal-field splitting reported previously is restored under high pressures, so that the orbital degrees of freedom disappears, resulting in the single phase transition that divides the system into high-temperature Mott insulating and low-temperature antiferromagnetic insulating phases.