mindspore.ops.AngleForce

class mindspore.ops.AngleForce(*args, **kwargs)

Calculate the force exerted by angles made of 3 atoms on the corresponding atoms. Assume the number of angles is m and the number of atoms is n.

$$d{r}_{ab}=(x_b-x_a,y_b-y_a,z_b-z_a)$$

$$d{r}_{cb}=(x_b-x_c,y_b-y_c,z_b-z_c)$$

$$theta=arccos(inne{r}_{p}roduct(d{r}_{ab},d{r}_{cb})/|d{r}_{ab}|/|d{r}_{cb}|)$$

$$F_a=-2\ast k\ast (theta-thet{a}_0)/sin(theta)\ast [cos(theta)/|d{r}_{ab}{|}^2\ast d{r}_{ab}-1/|d{r}_{ab}|/|d{r}_{cb}|\ast d{r}_{cb}]$$

$$F_c=-2\ast k\ast (theta-thet{a}_0)/sin(theta)\ast [cos(theta)/|d{r}_{cb}{|}^2\ast d{r}_{cb}-1/|d{r}_{cb}|/|d{r}_{ab}|\ast d{r}_{ab}]$$

$$F_b=-F_a-F_c$$

Parameters

angle_numbers (int32) – the number of angles m.

Inputs:

• uint_crd_f (Tensor, uint32) - [n, 3], the unsigned int coordinate value of each atom.

• scaler_f (Tensor, float32) - [3,], the 3-D scale factor between the real space float coordinates and the unsigned int coordinates.

• atom_a (Tensor, int32) - [m,], the 1st atom index of each angle.

• atom_b (Tensor, int32) - [m,], the 2nd and the central atom index of each angle.

• atom_c (Tensor, int32) - [m,], the 3rd atom index of each angle.

• angle_k (Tensor, float32) - [m,], the force constant for each angle.

• angle_theta0 (Tensor, float32) - [m,], the equilibrium position value for each angle.

Outputs:

• frc_f (Tensor, float32) - [n, 3], the force felt by each atom.

Supported Platforms:

GPU