High pressure phase transition and elastic behavior of TlX (X=N, P, As) semiconductors

► We have investigated the high-pressure structural transition of TlX compounds. ► An interaction potential model (IPM) has been developed. ► Phase transition pressures are associated with a sudden collapse in volume. ► Our model is able to explain Cauchy violations. ► We have extended our study to elastic and mechanical properties of TlX compounds.