Hüter, C., Friák, M., Weikamp, M., Neugebauer, J., Goldenfeld, N. D., Svendsen, B., et al. (2016). Nonlinear elastic effects in phase field crystal and amplitude equations: Comparison to ab initio simulations of bcc metals and graphene. Physical Review B, 93(21): 214105. doi:10.1103/PhysRevB.93.214105.