# **LAMMPS(mpich)下載方法**

# **1.準備安裝檔案:**

1. mkdir lammps #新建lammps文件夾
2. cd lammps/ #進入lammps/
3. wget http://www.fftw.org/fftw-3.3.8.tar.gz #下載fftw-3.3.8.tar.gz
4. wget http://www.mpich.org/static/downloads/3.3.1/mpich-3.3.1.tar.gz #下載mpich-3.3.1.tar.gz
5. wget https://lammps.sandia.gov/tars/lammps-stable.tar.gz #下載lammps-stable.tar.gz

# **2.解壓縮安裝檔案:**

1. tar -xvf fftw-3.3.8.tar.gz #解壓縮後為fftw-3.3.8
2. tar -xvf mpich-3.3.1.tar.gz #解壓縮後為mpich-3.3.1
3. tar -xvf lammps-stable.tar.gz #解壓縮後為lammps-7Aug19(不一定)

# **3.安装fftw**

lammps/ 文件夾下
1. mkdir fftw3 #新建fftw3文件夹
2. cd fftw-3.3.8/ #進入fftw-3.3.8/
3. ./configure --prefix=/share/home/.../lammps/fftw3/ --enable-shared=yes #/share/home/.../lammps/fftw3/安装到此目錄下，自指定
4. make <font color='#f00'>**-j**</font> 核心數
5. make install

# **4.安装mpich:**

lammps/ 文件夹下
1. mkdir mpich3
2. cd mpich-3.3.1/
3. ./configure --prefix=/share/home/.../lammps/mpich3/
4. make <font color='#f00'>**-j**</font> 核心數
5. make install

# **5.安装lammps:**

lammps/ 文件夹下
1. cd lammps-7Aug19(不一定)/src/MAKE/
2. vi Makefile.mpi #修改mpi和fftw鏈接路径

---

CC = g++ #需修改
CCFLAGS = -g -O3 <font color='#f00'>**-std=c++11**</font>

LINK = g++ #需修改

MPI_INC = -DMPICH_SKIP_MPICXX -DOMPI_SKIP_MPICXX=1 -I/ <font color='#f00'>**root**</font>/lammps/mpich3/include #需安自定修改路径
MPI_PATH = -L/ <font color='#f00'>**root**</font>/lammps/mpich3/lib #需安自定修改路径
MPI_LIB = -lmpich -lmpl -lpthread #需修改

FFT_INC = -DFFT_FFTW3 -I/ <font color='#f00'>**root**</font>/lammps/fftw3/include #需安自定修改路径
FFT_PATH = -L/ <font color='#f00'>**root**</font>/lammps/fftw3/lib #需安自定修改路径
FFT_LIB = -lfftw3 #需修改

---
3. cd .. #返回上層src文件夾
4. make clean-all
5. make yes-all
6. make no-lib
7. make mpi

make mpi成功會生成lmp_mpi執行文件

以下是檢查的指令
---
make ps # check which packages are currently installed
make yes-name # install a package with name
make no-name # un-install a package with name

---

# **6.建立軟鏈:**

1. ln -s /share/**root**/.../lmp_mpi /usr/bin/lmp_mpi #為lmp_mpi創建軟鏈

# **7.在~/.bashrc加PATH:**

#MPICH
PATH=/root/lammps/mpich3/bin:$PATH;export PATH

#lmp_mpi
export PATH=$PATH:/root/lammps/lammps-29Oct20/src

#libmpi.so.12
export LD_LIBRARY_PATH=/root/lammps/mpich3/lib:$LD_LIBRARY_PATH

最後要source ~/.bashrc

---
以下指令可以查找有無作用與路徑
which <font color='#f00'>**mpiexec**</font>

which <font color='#f00'>**mpicc**</font>

which lmp_mpi

---

# **8.测试:**

1. cd lammps-7Aug19(不一定)/examples/shear
2. mpirun -np 幾核心 lmp_mpi -in in.shear #調用幾核心運行

# **資料網址:**
1. https://www.jianshu.com/p/aabc4c340ac7
2. https://www.jianshu.com/p/6e8cad600217
3. https://stackoverflow.com/questions/14769599/mpi-error-loading-shared-libraries
4. https://lammps.sandia.gov/doc/Build_settings.html