Thehighpressureequationofstateforcarbonisconstructedbysomesimplephysicalmodels.Forsolidstate,amultiphaseequationofstateisconsidered,whichincludesfoursolidstates.Forliquidstate,theliquidperturbationtheoryofCRISmodelisused.Inthehightemperature,theelectroniccontributionisobtainedbytheionizationequilibriumtheory.Theresultofourcalculationbasedontheabovemodelsiscomparedwiththefirstprincipledensityfunctionalcalculationandtheothermodels.TheHugoniotandthephasediagramofcarbonarealsocomparedwiththeexperiments.Theresultsaresatisfactory.
