| 51 |  |  | 
| 52 |  | public: | 
| 53 |  | ForceFieldOptions() { | 
| 54 | < | DefineOptionalParameter(MixingRule, "arthimatic"); | 
| 54 | > | DefineOptionalParameter(MixingRule, "arithmetic"); | 
| 55 |  | } | 
| 56 |  |  | 
| 57 |  | ForceFieldOptions(const ForceFieldOptions&); | 
| 58 |  | ForceFieldOptions& operator = (const ForceFieldOptions&); | 
| 59 |  |  | 
| 60 |  | void validateOptions() { | 
| 61 | < | CheckParameter(MixingRule, isEqualIgnoreCase(std::string("arthimatic")) || | 
| 62 | < | isEqualIgnoreCase(std::string("geometric"))); | 
| 61 | > | CheckParameter(MixingRule, isEqualIgnoreCase(std::string("arithmetic")) || isEqualIgnoreCase(std::string("geometric"))); | 
| 62 |  |  | 
| 63 |  | } | 
| 64 |  |  |