For example, As exhibits a decrease (increase) of IpCOHP(2c) along the primary d1 (secondary d2) bonds in As-I from -3.451 (-0.835) at 0 GPa to -3.135 (-2.733) at 35 GPa. This trend is indicative of the decrease (increase) of the strength of the primary (secondary) bond until they reach the same value once the As-II structure is attained. This pressure-induced "trans influence", i.e. influence of the secondary bond on the primary bond, is clearly evidenced for As in Fig. by the inverse pressure dependence of the ES values of both primary and secondary bonds. On the other hand, the increase of the absolute value of ICOBI(3c) from -0.046 at 0 GPa to -0.076 at 35 GPa is clearly indicative of the increase of the multicenter (in this case three-center) interaction as one goes from As-I to As-II. According to Dronkowski and coworkers, the negative value of ICOBI(3c) indicates that these multicenter bonds are ERMBs ; however, we think that this interpretation of the value of ICOBI(3c) should be revisited as we will further discuss in section 4.