Systemsofphotosyntheticreactioncentreshavebeenmodelledasheatengines,whileithasalsobeenreportedthattheefficiencyandpowerofsuchheatenginescanbeenhancedbyquantuminterference—atraitthathasattractedmuchinterest.Wecomparetwodefinitionsoftheworkofsuchaphotosyntheticheatengine,i.e.definitionAusedbyWeimeretal.andBbyDorfmanetal.Wealsointroduceacoherentinteractionbetweendonorandacceptor(CIDA)todemonstrateareversibleenergytransport.Weshowthatthesetwodefinitionsofworkcanimpartcontradictoryresults,thatis,CIDAenhancesthepowerandefficiencyofthephotosyntheticheatenginewithdefinitionBbutnotwithA.Additionally,wefindthatbothreversibleandirreversibleexcitation-energytransportcanbedescribedwithdefinitionA,butdefinitionBcanonlymodelirreversibletransport.Asaresult,weconcludethatdefinitionAismoresuitableforphotosyntheticsystemsthandefinitionB.
