產(chǎn)生碳納米管坐標(biāo)的Matlab程序

1、產(chǎn)生碳納米管坐標(biāo)的Matlab程序 以下是一個(gè)產(chǎn)生任意(m,n)碳管坐標(biāo)的一個(gè) Matlab程序。只需把下面的程序 copy ,存成 creatCNT.m，即可用 Matlab直接運(yùn)行。比如在 Matlab提示符下輸入 creatCNT(8,0) 則產(chǎn)生(8,0)碳納米管的坐標(biāo)，輸出文件為 nanotube.xyz 和nanotube.pdb 格式?？梢杂闷?他的可視化軟件打開。 % function X TransVec NumAtom Diameter ChiralAngle=createCNT(n,m) %This function creates the coordinates of

2、a (n,m) nanotube, with nm %Usage: % X TransVec NumAtom Diameter ChiralAngle=createCNT(8,0); % X - coordinates of atoms in the nanotube unit cell % TransVec - Translational Vector T of the nanotube % NumAtom - Number of atoms in one unit cell of nanotube % Diamter - diameter of the nanotube % ChiralA

3、ngle - chiral angle of the nanotube % by bshan 2005 %change order if nm if(n0)&(j1=2) error(more than 1 pair p,q strange!) end %symmetry vector (np,nq) np = nnp(1); nq = nnq(1); %msg=sprintf(the symmetry vector is %d %d,np,nq); %disp(msg); % % r:|R| , c:|C_h|, t:|T| % lp = np*np + nq*nq + np*nq; r=a

4、*sqrt(lp); c=a*l; t=sq3*c/ndr; % nn: the number of hexagon in the unit cell N % rs: radius of the tube if(2*nn)nk) error(parameter nk is too small!) end rs=c/(2.0d0*pi); %msg=sprintf(radius=%f ,t=%f,rs,t); %disp(msg); % q1: the chiral angle for C_h % q2: the chiral angle for R % q3: the chiral betwe

5、en C_h and R q1=atan(sq3*m)/(2*n+m); q2=atan(sq3*nq)/(2*np+nq); q3=q1-q2; % q4: a period of an angle for the A atom % q5: the difference of the angle between the A and B atom q4=2.0*pi/nn; q5=acc*cos(pi/6.0d0)-q1)/c*2.0*pi; % h1: % h2: Delta z between the A and B atom h1=abs(t)/abs(sin(q3); h2=acc*s

6、in(pi/6.0)-q1); % The A atom ii=0; for i=0:nn-1 x1=0; y1=0; z1=0; k=floor(i*abs(r)/h1); x1=rs*cos(i*q4); y1=rs*sin(i*q4); z1=(i*abs(r)-k*h1)*sin(q3); kk2=abs(floor(z1+0.0001)/t); % Check the A atom is in the unit cell 0=z1=t-0.0001) z1=z1-t*kk2; elseif(z10) z1=z1+t*kk2; else end ii=ii+1; x(ii)=x1; y

7、(ii)=y1; z(ii)=z1; % The B atom z3=(i*abs(r)-k*h1)*sin(q3)-h2; ii=ii+1; % Check the B atom is in the unit cell 0=z3=0)&(z3=t-0.0001) z2 =z2-t*kk; elseif(z20) z2 =z2+t*kk; else end x(ii)=x2; y(ii)=y2; z(ii)=z2; end end %total number of atoms ntotal=2*nn; for i=1:ntotal X(i,) =x(i) y(i) z(i); end Tran

8、sVec=t; NumAtom=ntotal; Diameter=rs*2; ChiralAngle=atan(sq3*n)/(2*m+n)/pi*180; %write coordinates to xyz file format fid=fopen(nanotube.xyz,w); fprintf(fid,%dn,size(X,1); fprintf(fid,created by GUI_TB programn); for i=1:ntotal fprintf(fid,C %f %f %f n,X(i,1),X(i,2),X(i,3); end fclose(fid); %write coordinates to pdb file format(for visualization using rasmol) fid=fopen(nanotube.pdb,w);