Environment Variables#

Configure NIM for BMD behavior at container startup using the following environment variables.

Required Variables#

Variable	Required	Default	Description
`NGC_API_KEY`	Yes (for NGC access)	–	NGC authentication key used to access the NIM container. The default MACE-MPA-0 checkpoint is downloaded separately from Hugging Face.

Variable	Type	Default	Description
`ALCHEMI_NIM_MODEL_TYPE`	string	`"mace"`	Model architecture: `mace`, `aimnet2`, or `tensornet`. Use `ALCHEMI_NIM_MODEL_PATH` to select the checkpoint.
`ALCHEMI_NIM_MODEL_PATH`	string	null	Path to the model file or directory inside the container.
`ALCHEMI_NIM_PBC`	bool	true	Backend PBC mode. When true, the request structure must include `cell`; when false, it must omit `cell`. Nested `atoms.pbc` values do not override this mode.
`ALCHEMI_NIM_BATCH_SIZE`	int	null	Batch size in atoms (`null` enables automatic estimation at startup).
`ALCHEMI_NIM_BATCH_SIZE_ESTIMATE_DATA`	string	`"omat24"`	Dataset used for auto-estimation: `omat24` (bulk materials), `omol25` (molecules), or `omc25` (molecular crystals).
`ALCHEMI_NIM_DFTD3_ENABLED`	bool	false	Enable DFT-D3(BJ) dispersion correction.
`ALCHEMI_NIM_DFTD3_PARAM`	string (JSON)	null	JSON string containing custom DFT-D3(BJ) parameters. Custom models require `a1`, `a2`, and `s8`. Refer to Configuration for details.

Variable	Required	Default	Description
`NIM_HTTP_API_PORT`	No	`8000`	HTTP port for the inference API.
`ALCHEMI_NIM_DISABLE_MODEL_DOWNLOAD`	No	false	Whether to disable the automatic startup download of the default MACE-MPA-0 checkpoint from Hugging Face. Set to `true` when mounting a user-provided model.

For launch examples, refer to Custom Models and Quickstart Guide.