code: def cal_k_vinet(p, k):
      
      v = cal_v_vinet(p, k)
      return cal_k_vinet_from_v(v, k[0], k[1], k[2])
docs: calculate bulk modulus in GPa
  
      :param p: pressure in GPa
      :param k: [v0, k0, k0p]
      :return: bulk modulus at high pressure in GPa