Effective Core Potentials

group ECPCompute

Functions

cuestStatus_t cuestECPCompute(

cuestHandle_t handle,

const cuestECPIntPlan_t plan,

const cuestECPComputeParameters_t parameters,

const cuestWorkspaceDescriptor_t *variableBufferSize,

cuestWorkspace_t *temporaryWorkspace,

double *outECPMatrix

)

Compute the effective core potential integral matrix using the provided plan.

The output buffer must be preallocated and sized for (nao × nao) elements, where nao is the number of atomic orbitals in the basis. Temporary workspace must be allocated using size returned by cuestECPComputeWorkspaceQuery.

Parameters:

• handle – [in] cuEST handle. Must not be NULL.

• plan – [in] ECP integral computation plan (opaque handle).

• parameters – [in] Handle to cuestECPComputeParameters_t. Must not be NULL.

• variableBufferSize – [in] User-provided descriptor for the amount of memory used to evaluate the ECP integrals. 2 GB is a good default buffer size for device memory. If an insufficient amount of memory is provided, the cuestECPCompute call will return CUEST_STATUS_EXCEPTION. If this occurs, increase the variableBufferSize and make the WorkspaceQuery and Compute calls again. This value MUST remain unchanged between the WorkspaceQuery call and the Compute call. Host memory is currently unused. Must not be NULL.

• temporaryWorkspace – [in] Temporary workspace buffers for computation (preallocated).

• outECPMatrix – [out] Output buffer for computed ECP matrix elements (size: nao × nao) on the GPU. Must not be NULL. Elements of this array are overwritten by the calculation results.

Returns:

• CUEST_STATUS_SUCCESS on success;

• CUEST_STATUS_INVALID_HANDLE if the cuEST handle is NULL;

• CUEST_STATUS_NULL_POINTER if any required pointer is NULL;

• CUEST_STATUS_INVALID_TYPE if opaque handles are not the correct type.

• CUEST_STATUS_EXCEPTION or CUEST_STATUS_UNKNOWN_ERROR otherwise.

• CUEST_STATUS_EXCEPTION often indicates variableBufferSize is too small.

cuestStatus_t cuestECPComputeWorkspaceQuery(

cuestHandle_t handle,

const cuestECPIntPlan_t plan,

const cuestECPComputeParameters_t parameters,

const cuestWorkspaceDescriptor_t *variableBufferSize,

cuestWorkspaceDescriptor_t *temporaryWorkspaceDescriptor,

double *outECPMatrix

)

Query the temporary workspace required (in bytes) for effective core potential matrix calculation.

This function computes the workspace requirements for a requested ECP calculation. Fill the provided workspace descriptor with host and device buffer sizes required. The outECPMatrix pointer may be NULL.

Parameters:

• handle – [in] cuEST handle. Must not be NULL.

• plan – [in] ECP integral computation plan (opaque handle).

• parameters – [in] Handle to cuestECPComputeParameters_t. Must not be NULL.

• variableBufferSize – [in] User-provided descriptor for the amount of memory used to evaluate the ECP integrals. 2 GB is a good default buffer size for device memory. If an insufficient amount of memory is provided, the cuestECPCompute call will return CUEST_STATUS_EXCEPTION. If this occurs, increase the variableBufferSize and make the WorkspaceQuery and Compute calls again. This value MUST remain unchanged between the WorkspaceQuery call and the Compute call. Host memory is currently unused. Must not be NULL.

• temporaryWorkspaceDescriptor – [out] Output descriptor for temporary workspace sizes. Must not be NULL.

• outECPMatrix – [in] User matrix buffer. May be NULL.

Returns:

• CUEST_STATUS_SUCCESS on success;

• CUEST_STATUS_INVALID_HANDLE if the cuEST handle is NULL;

• CUEST_STATUS_NULL_POINTER if any required pointer is NULL;

• CUEST_STATUS_INVALID_TYPE if opaque handles are not the correct type.

• CUEST_STATUS_EXCEPTION or CUEST_STATUS_UNKNOWN_ERROR otherwise.

cuestStatus_t cuestECPDerivativeCompute(

cuestHandle_t handle,

const cuestECPIntPlan_t plan,

const cuestECPDerivativeComputeParameters_t parameters,

const cuestWorkspaceDescriptor_t *variableBufferSize,

cuestWorkspace_t *temporaryWorkspace,

const double *densityMatrix,

double *outGradient

)

Compute the electronic gradient (derivative) of the effective core potential integral matrix using the provided plan and density matrix.

Both the input density matrix and the output gradient must be preallocated. The density matrix must be an (nao x nao) array and the output gradient must have space for (natom x 3) elements, where nao is the number of atomic orbitals and natom the number of atoms in the system. All required temporary workspace must be allocated by the user prior to calling this function using size returned by cuestECPDerivativeComputeWorkspaceQuery.

Parameters:

• handle – [in] cuEST handle. Must not be NULL.

• plan – [in] ECP integral computation plan (opaque handle).

• parameters – [in] Handle to cuestECPDerivativeComputeParameters_t. Must not be NULL.

• variableBufferSize – [in] User-provided descriptor for the amount of memory used to evaluate the ECP integrals. 2 GB is a good default buffer size for device memory. If an insufficient amount of memory is provided, the cuestECPDerivativeCompute call will return CUEST_STATUS_EXCEPTION. If this occurs, increase the variableBufferSize and make the WorkspaceQuery and Compute calls again. This value MUST remain unchanged between the WorkspaceQuery call and the Compute call. Host memory is currently unused. Must not be NULL.

• temporaryWorkspace – [in] Temporary workspace buffers for computation (preallocated).

• densityMatrix – [in] Pointer to input density matrix (size: nao × nao) on the GPU. Must not be NULL.

• outGradient – [out] Output buffer for computed ECP gradient (size: natom × 3) on the GPU. Must not be NULL. Elements of this array are overwritten by the calculation results.

Returns:

• CUEST_STATUS_SUCCESS on success;

• CUEST_STATUS_INVALID_HANDLE if the cuEST handle is NULL;

• CUEST_STATUS_NULL_POINTER if any required pointer is NULL;

• CUEST_STATUS_INVALID_TYPE if opaque handles are not the correct type.

• CUEST_STATUS_EXCEPTION or CUEST_STATUS_UNKNOWN_ERROR otherwise.

• CUEST_STATUS_EXCEPTION often indicates variableBufferSize is too small.

cuestStatus_t cuestECPDerivativeComputeWorkspaceQuery(

cuestHandle_t handle,

const cuestECPIntPlan_t plan,

const cuestECPDerivativeComputeParameters_t parameters,

const cuestWorkspaceDescriptor_t *variableBufferSize,

cuestWorkspaceDescriptor_t *temporaryWorkspaceDescriptor,

const double *densityMatrix,

double *outGradient

)

Query the temporary workspace required (in bytes) for electronic gradient (derivative) of the effective core potential matrix using the supplied integral plan and density matrix.

This function computes the workspace requirements for a requested ECP gradient calculation. Fill the provided workspace descriptor with host and device buffer sizes required. The outGradient pointer may be NULL.

Parameters:

• handle – [in] cuEST handle. Must not be NULL.

• plan – [in] ECP integral computation plan (opaque handle).

• parameters – [in] Handle to cuestECPDerivativeComputeParameters_t. Must not be NULL.

• variableBufferSize – [in] User-provided descriptor for the amount of memory used to evaluate the ECP integrals. 2 GB is a good default buffer size for device memory. If an insufficient amount of memory is provided, the cuestECPDerivativeCompute call will return CUEST_STATUS_EXCEPTION. If this occurs, increase the variableBufferSize and make the WorkspaceQuery and Compute calls again. This value MUST remain unchanged between the WorkspaceQuery call and the Compute call. Host memory is currently unused. Must not be NULL.

• temporaryWorkspaceDescriptor – [out] Output descriptor for temporary workspace sizes. Must not be NULL.

• densityMatrix – [in] Pointer to input density matrix. May be NULL.

• outGradient – [in] User buffer. May be NULL.

Returns:

• CUEST_STATUS_SUCCESS on success;

• CUEST_STATUS_INVALID_HANDLE if the cuEST handle is NULL;

• CUEST_STATUS_NULL_POINTER if any required pointer is NULL;

• CUEST_STATUS_INVALID_TYPE if opaque handles are not the correct type.

• CUEST_STATUS_EXCEPTION or CUEST_STATUS_UNKNOWN_ERROR otherwise.