import torch


def radial_gaussian(distances, r0s, alpha=1.):
    """
    Evaluates Gaussians on the radial values of the distances.
    """
    gauss_arg = distances.unsqueeze(-1) - torch.unsqueeze(r0s, dim=-2)
    basis_fxn = torch.exp(-alpha * gauss_arg**2)
    return basis_fxn