蒙特卡罗模拟在材料科学中应用举例.ppt

蒙特卡罗模拟在材料科学中应用举例;1、MonteCarloSimulationofDiffusion;

;; !MonteCarloSimulationofOneDimensionalDiffusion

INTEGERX,XX(1:1000,1:1000)

REALXXM(1:1000)

! X:INSTANTANEOUSPOSITIONOFATOM

! XX(J,I)：X*X,J:第几天实验,I:第几步跳跃

! XXM(I):THEMEANOFXX

WRITE(*,*)实验天数Jt，实验次数Ic

READ(*,*)Jt,Ic

ISEED=RTC()

DOJ=1,Jt!第几天实验

X=0!每天都是从原点出发

DOI=1,Ic!第几步跳跃

RN=RAN(ISEED)

IF(RN0.5)THEN

X=X+1

ELSE

X=X-1

ENDIF

XX(J,I)=X*X!记录下原子每天每次跳动后离原点的距离

ENDDO

ENDDO

OPEN(1,FILE=“f:\DIF1.DAT)

DOI=1,Ic

XXM=0.0

XXM(I)=1.0*SUM(XX(1:Jt,I))/Jt!!

WRITE(1,*)I,XXM(I)

ENDDO

CLOSE(1)

END;二维随机行走随机确实定;;! MonteCarloSimulationofTwoDimensionalDiffusion

INTEGERX,XY(1:1000,1:1000),y,XN(1:4),YN(1:4),RN

REALXYM(1:1000)

! X:INSTANTANEOUSPOSITIONOFATOM

! XY(J,I)：X*Y,J:第几天实验,I:第几步跳跃

! XYM(I):THEMEANOFXY

WRITE(*,*)实验天数Jt，实验次数Ic

READ(*,*)Jt,Ic

XN=(/0,0,-1,1/)

YN=(/-1,1,0,0/)

ISEED=RTC()

DOJ=1,Jt!第几天实验

X=0!!!

Y=0!!!

DOI=1,Ic!第几步跳跃

RN=4*RAN(ISEED)+1

X=X+YN(RN)

Y=Y+YN(RN)

XY(J,I)=X*X+Y*Y

ENDDO

ENDDO

OPEN(1,FILE=C:\DIF2.DAT)

DOI=1,Ic

XYM=0.0

XYM(I)=1.0*SUM(XY(1:Jt,I))/Jt!!

WRITE(1,*)I,XYM(I)

ENDDO

CLOSE(1)！做三维空间随机行走？

END;SimulationofRecrystallisationGrainGrowthbyMeansofaMonteCarloModel;2Algorithm(proposedbyAndersonetal.1984);EnergyE_iofalatticesite:

(1)

J:Energyfactor

NN:Numberofnearestneighbours

:Kronecker-delta;;2.蒙特卡罗模拟双晶粒的长大;画一个圆晶粒;画晶界;转变规那么——能量最小原理;界面能;任意选邻居再计算能量;能量判断;MC模拟双晶粒的长大;双晶长大/收缩;多晶的长大; USEMSFLIB

PARAMETERIR=400,JR=400,NMAX=1000

INTEGERIS(0:IR+1,0:JR+1),TMAX,ISB(1:8),ISTR,T,NR,IX,IY,X,Y,RD

INTEGERXN(1:8),YN(1:8),IGV(0:NMAX)

XN=(/-1,0,1,-1,1,-1,0,1/)

YN=(/-1,0,-1,0,0,1,1,1/)

WRITE(*,*)PLEASEINPUTTHETIMESTEP

READ(*,*)TMAX

ISEED=RTC()

IGV