64 CubicBondType(RealType r0, RealType k3, RealType k2, RealType k1,
67 k3_(k3), k2_(k2), k1_(k1), k0_(k0) {}
69 void setForceConstant(RealType k3, RealType k2, RealType k1, RealType k0) {
76 void getForceConstant(RealType& k3, RealType& k2, RealType& k1,
84 virtual void calcForce(RealType r, RealType& V, RealType& dVdr) {
86 RealType dr2 = dr * dr;
87 RealType dr3 = dr2 * dr;
89 V = k0_ + k1_ * dr + k2_ * dr2 + k3_ * dr3;
90 dVdr = k1_ + 2.0 * k2_ * dr + 3.0 * k3_ * dr2;