####orca5.0.4

export PATH=$PATH:/home/WYW2/software/orca_5_0_4

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/WYW2/software/orca_5_0_4

alias orca='/home/WYW2/software/orca_5_0_4/orca'

###for openMPI 4.11

export PATH=/home/WYW2/program/openmpi411/bin/:$PATH

export LD_LIBRARY_PATH=/home/WYW2/program/openmpi411/lib/:$LD_LIBRARY_PATH

! QMMM B3LYP def2-SVP def2/J RIJCOSX OPT

%MAXCORE 3000

%scf

      convergence normal tight (单点） or loose   

       MaxIter 100                   # Max. no. of SCF iterations

end 

%pal nprocs 4    end                   # any number (positive integer)        

or

! PAL4 # everything from PAL2 to PAL8 and Pal16 is recognized

%qmmm                                  # use either

ORCAFFFilename "prmtop.ORCAFF.prms"

QMAtoms {0:4} end                 # 1. list of atoms (counting starts from 0)

or

Use_QM_InfoFromPDB true      # 2. get the definition from the pdb file. Default false.

ActiveAtoms {0:5 224:243} end

end                                         # If (2) is set to true, (1) is ignored

*pdbfile 0 1 ubq.pdb 

注意：orca的原子序号是从0开始

不同的程序用的理论方法在定义上可能存在差异，典型的是B3LYP定义的差异。在B3LYP定义之初没说清楚其VWN局域相关泛函用的具体形式，导致不同程序用了不同的形式，有人在Chem. Phys. Lett., 268, 345 (1997)中还做了专门讨论和对比测试。Gaussian中默认用的是VWN3，TURBOMOLE、GAMESS-US、CRYSTAL、ORCA等默认用的是VWN5。如果要用Gaussian的B3LYP，在ORCA里应当写B3LYP/G，在GAMESS-US里应当写B3LYPV1R（而非B3LYPV3，这点经过实测确认），在Dalton里应该写B3LYPg。