Digital Object Identifier (DOI) https://doi.org/10.1063/1.3636790 https://doi.org/10.1063/1.4756349 https://doi.org/10.1063/1.4825818 https://doi.org/10.1063/1.4912375 https://doi.org/10.1063/1.4951870 https://doi.org/doi 10.1063/1.4825818