文件propene.mol是ACD/ChemSketch所生成的丙烯分子的mol格式文件，读出其中的坐标数据，求出所有的任意两原子之间的距离，写入文件data.txt中（提示需要对原子按顺序进行编号）。
图片中框起来的是原子坐标。
文件内容用记事本打开后如下：
ACD/Labs06161409443D
9 8 0 0 0 0 0 0 0 0 1 V2000 -1.3862 0.2568 0.3311 C 0 0 0 0 0 0 0 0 0 0 0 0 -0.0048 -0.4184 0.2913 C 0 0 0 0 0 0 0 0 0 0 0 0 1.1277 0.3436 0.3051 C 0 0 0 0 0 0 0 0 0 0 0 0 -1.7416 0.4506 -0.7259 H 0 0 0 0 0 0 0 0 0 0 0 0 -2.1226 -0.4224 0.8580 H 0 0 0 0 0 0 0 0 0 0 0 0 -1.3099 1.2385 0.8893 H 0 0 0 0 0 0 0 0 0 0 0 0 0.1882 -1.5328 0.2496 H 0 0 0 0 0 0 0 0 0 0 0 0 2.1443 -0.1529 0.2758 H 0 0 0 0 0 0 0 0 0 0 0 0 1.0501 1.4720 0.3460 H 0 0 0 0 0 0 0 0 0 0 0 0 1 2 1 0 0 0 0 1 4 1 0 0 0 0 1 5 1 0 0 0 0 1 6 1 0 0 0 0 2 3 2 0 0 0 0 2 7 1 0 0 0 0 3 8 1 0 0 0 0 3 9 1 0 0 0 0M END
代码如下，供参考
program testimplicit none
character(len=200) :: string
real(8),allocatable :: xyz(:,:)
real(8) :: rij
integer :: natoms,nbonds
integer :: i,j
open(10,file='propene.mol',action='read')
read(10,*)
read(10,*)
read(10,*)
read(10,'(a200)') string
read(string(1:3),*) natoms
read(string(4:6),*) nbonds
allocate(xyz(natoms,3))
do i = 1,natoms
read(10,*) xyz(i,1:3)
! print '(3f14.8,x)', xyz(i,:)
end do
close(10)
open(11,file='data.txt',action='write')
do i = 1,natoms-1
do j = i+1,natoms
rij = dsqrt( sum( (xyz(i,:) - xyz(j,:))**2 ) )
write(11,*) i,j,rij
write(*,*) i,j,rij
end do
end do
close(11)
stop
end program
运行结果，同时保存文件data.txt中
1 2 1.538097864246621 3 2.51553243866979
1 4 1.13186421447098
1 5 1.13191042490119
1 6 1.13187623881765
1 7 2.38496242528053
1 8 3.55462268461788
1 9 2.72258897742572
2 3 1.36506069095846
2 4 2.19233461862007
2 5 2.19231424070547
2 6 2.19230646124122
2 7 1.13175759330344
2 8 2.16549331793012
2 9 2.16550646731890
3 4 3.05078555293551
3 5 3.38480494268134
3 6 2.66158400393450
3 7 2.09919447884182
3 8 1.13174480338988
3 9 1.13180436913806
4 5 1.84825031042876
4 6 1.84824845191332
4 7 2.93421264566834
4 8 4.05805790372685
4 9 3.16003424981439
5 6 1.84933766251596
5 7 2.63494503927501
5 8 4.31486068141255
5 9 3.73053892219341
6 7 3.21459536956053
6 8 3.77410570201737
6 9 2.43296057099165
7 8 2.39397946106478
7 9 3.12745705166354
8 9 1.96023000946318
其中
4 5 1.84825031042876表示第4个原子和第5个原子间的距离为1.84825031042876 (Angstrom)
