deepmd.tf.descriptor.se_a_mask

Module Contents

Classes

DescrptSeAMask

DeepPot-SE constructed from all information (both angular and radial) of

class deepmd.tf.descriptor.se_a_mask.DescrptSeAMask(sel: List[int], neuron: List[int] = [24, 48, 96], axis_neuron: int = 8, resnet_dt: bool = False, trainable: bool = True, type_one_side: bool = False, exclude_types: List[List[int]] = [], seed: int | None = None, activation_function: str = 'tanh', precision: str = 'default', uniform_seed: bool = False, stripped_type_embedding: bool = False, **kwargs)

Bases: deepmd.tf.descriptor.se_a.DescrptSeA

DeepPot-SE constructed from all information (both angular and radial) of atomic configurations. The embedding takes the distance between atoms as input.

The descriptor \(\mathcal{D}^i \in \mathcal{R}^{M_1 \times M_2}\) is given by [1]

\[\mathcal{D}^i = (\mathcal{G}^i)^T \mathcal{R}^i (\mathcal{R}^i)^T \mathcal{G}^i_<\]

where \(\mathcal{R}^i \in \mathbb{R}^{N \times 4}\) is the coordinate matrix, and each row of \(\mathcal{R}^i\) can be constructed as follows

\[(\mathcal{R}^i)_j = [ \begin{array}{c} s(r_{ji}) & \frac{s(r_{ji})x_{ji}}{r_{ji}} & \frac{s(r_{ji})y_{ji}}{r_{ji}} & \frac{s(r_{ji})z_{ji}}{r_{ji}} \end{array} ]\]

where \(\mathbf{R}_{ji}=\mathbf{R}_j-\mathbf{R}_i = (x_{ji}, y_{ji}, z_{ji})\) is the relative coordinate and \(r_{ji}=\lVert \mathbf{R}_{ji} \lVert\) is its norm. The switching function \(s(r)\) is defined as:

\[\begin{split}s(r)= \begin{cases} \frac{1}{r}, & r<r_s \\ \frac{1}{r} \{ {(\frac{r - r_s}{ r_c - r_s})}^3 (-6 {(\frac{r - r_s}{ r_c - r_s})}^2 +15 \frac{r - r_s}{ r_c - r_s} -10) +1 \}, & r_s \leq r<r_c \\ 0, & r \geq r_c \end{cases}\end{split}\]

Each row of the embedding matrix \(\mathcal{G}^i \in \mathbb{R}^{N \times M_1}\) consists of outputs of a embedding network \(\mathcal{N}\) of \(s(r_{ji})\):

\[(\mathcal{G}^i)_j = \mathcal{N}(s(r_{ji}))\]

\(\mathcal{G}^i_< \in \mathbb{R}^{N \times M_2}\) takes first \(M_2\) columns of \(\mathcal{G}^i\). The equation of embedding network \(\mathcal{N}\) can be found at deepmd.tf.utils.network.embedding_net(). Specially for descriptor se_a_mask is a concise implementation of se_a. The difference is that se_a_mask only considered a non-pbc system. And accept a mask matrix to indicate the atom i in frame j is a real atom or not. (1 means real atom, 0 means ghost atom) Thus se_a_mask can accept a variable number of atoms in a frame.

Parameters:

sellist[int]

sel[i] specifies the maxmum number of type i atoms in the neighbor list.

neuronlist[int]

Number of neurons in each hidden layers of the embedding net \(\mathcal{N}\)

axis_neuron

Number of the axis neuron \(M_2\) (number of columns of the sub-matrix of the embedding matrix)

resnet_dt

Time-step dt in the resnet construction: y = x + dt * phi (Wx + b)

trainable

If the weights of embedding net are trainable.

seed

Random seed for initializing the network parameters.

type_one_side

Try to build N_types embedding nets. Otherwise, building N_types^2 embedding nets

exclude_typesList[List[int]]

The excluded pairs of types which have no interaction with each other. For example, [[0, 1]] means no interaction between type 0 and type 1.

activation_function

The activation function in the embedding net. Supported options are {0}

precision

The precision of the embedding net parameters. Supported options are {1}

uniform_seed

Only for the purpose of backward compatibility, retrieves the old behavior of using the random seed

References

[1]

Linfeng Zhang, Jiequn Han, Han Wang, Wissam A. Saidi, Roberto Car, and E. Weinan. 2018. End-to-end symmetry preserving inter-atomic potential energy model for finite and extended systems. In Proceedings of the 32nd International Conference on Neural Information Processing Systems (NIPS’18). Curran Associates Inc., Red Hook, NY, USA, 4441-4451.

get_rcut() → float

Returns the cutoff radius.

compute_input_stats(data_coord: list, data_box: list, data_atype: list, natoms_vec: list, mesh: list, input_dict: dict, **kwargs) → None

Compute the statisitcs (avg and std) of the training data. The input will be normalized by the statistics.

Parameters:

data_coord

The coordinates. Can be generated by deepmd.tf.model.make_stat_input

data_box

The box. Can be generated by deepmd.tf.model.make_stat_input

data_atype

The atom types. Can be generated by deepmd.tf.model.make_stat_input

natoms_vec

The vector for the number of atoms of the system and different types of atoms. Can be generated by deepmd.tf.model.make_stat_input

mesh

The mesh for neighbor searching. Can be generated by deepmd.tf.model.make_stat_input

input_dict

Dictionary for additional input

**kwargs

Additional keyword arguments.

build(coord_: deepmd.tf.env.tf.Tensor, atype_: deepmd.tf.env.tf.Tensor, natoms: deepmd.tf.env.tf.Tensor, box_: deepmd.tf.env.tf.Tensor, mesh: deepmd.tf.env.tf.Tensor, input_dict: Dict[str, Any], reuse: bool | None = None, suffix: str = '') → deepmd.tf.env.tf.Tensor

Build the computational graph for the descriptor.

Parameters:

coord_

The coordinate of atoms

atype_

The type of atoms

natoms

The number of atoms. This tensor has the length of Ntypes + 2 natoms[0]: number of local atoms natoms[1]: total number of atoms held by this processor natoms[i]: 2 <= i < Ntypes+2, number of type i atoms

box_tf.Tensor

The box of the system

mesh

For historical reasons, only the length of the Tensor matters. if size of mesh == 6, pbc is assumed. if size of mesh == 0, no-pbc is assumed.

input_dict

Dictionary for additional inputs

reuse

The weights in the networks should be reused when get the variable.

suffix

Name suffix to identify this descriptor

Returns:

descriptor

The output descriptor

prod_force_virial(atom_ener: deepmd.tf.env.tf.Tensor, natoms: deepmd.tf.env.tf.Tensor) → Tuple[deepmd.tf.env.tf.Tensor, deepmd.tf.env.tf.Tensor, deepmd.tf.env.tf.Tensor]

Compute force and virial.

Parameters:

atom_ener

The atomic energy

natoms

The number of atoms. This tensor has the length of Ntypes + 2 natoms[0]: number of local atoms natoms[1]: total number of atoms held by this processor natoms[i]: 2 <= i < Ntypes+2, number of type i atoms

Returns:

force

The force on atoms

virial

None for se_a_mask op

atom_virial

None for se_a_mask op

classmethod update_sel(global_jdata: dict, local_jdata: dict)

Update the selection and perform neighbor statistics.

Parameters:

global_jdatadict

The global data, containing the training section

local_jdatadict

The local data refer to the current class