lambda_spin_response

This keyword sets the weight of grouped magnetic-response loss:

lambda_spin_response <weight>

The weight must be finite and non-negative and defaults to 0. A positive value requires spin_version 1 and a valid response.xyz in the working directory. With weight 0, the file is not opened. See that file’s page for required labels, group metadata, and data-splitting rules.

All complete groups are evaluated for every candidate in every SNES generation after initialization. Ordinary batch settings do not split response groups. Response frames contribute only this loss and reuse the energy reference and scaler obtained from ordinary training data. Test reporting and model selection are unchanged; no separate response validation loss is added.

The loss compares predicted and target generalized magnetic responses along each path. Each group has equal weight. Its uncentered target-response RMS, floored at \(10^{-6}\), normalizes a centered-shape Huber term and a group-mean Huber term; the latter has weight 0.25. Coordinates do not add a separate reliability weight. This objective supplements per-component magnetic-force RMSE when relative response along a controlled rotation path matters. See Grouped magnetic response for the response and tangent definitions.