Installing the VTST Transition State Tools

Procedure

Use PuTTY to log in to the server as the root user.
Upload the VTSTcode installation package to the directory where the VASP is installed.
Run the following commands to decompress the VTST installation package:
```
cd /path/to/VASP
tar -xzvf vtstcode-179.tgz
```
Run the following command to back up the chain.F file in the src directory of the VASP installation package:
```
cp vasp-5.4.4/src/chain.F / vasp-5.4.4/src/chain.F_bak
```
Run the following command to copy files in the vtstcode-179 directory to the src directory:
```
cp vtstconde-179/* vasp-5.4.4/src/
```
Run the following commands to modify the src/main.F file:
1. Run the following command to edit the case file:
```
vi vasp-5.4.4/src/main.F
```
2. Press i to enter the insert mode. Pay attention to the content in bold in line 3147.
  Before the modification:
```
CALL CHAIN_FORCE(T_INFO%NIONS,DYN%POSION,TOTEN,TIFOR, &  LATT_CUR%A,LATT_CUR%B,IO%IU6)
```
  After the modification:
```
CALL CHAIN_FORCE(T_INFO%NIONS,DYN%POSION,TOTEN,TIFOR, &  TSIF,LATT_CUR%A,LATT_CUR%B,IO%IU6)
```
3. Press Esc, type :wq!, and press Enter to save the file and exit.
Run the following command to modify the compilation configuration file:
1. Open the compilation configuration file.
```
vi vasp-5.4.4/src/.objects
```
2. Press i to enter the insert mode and add the following content between line 71 and line 72:
```
bfgs.o dynmat.o instanton.o lbfgs.o sd.o cg.o dimer.o bbm.o \
fire.o lanczos.o neb.o qm.o opt.o \
```
  Ensure that no space exists after a backslash (\). Replace spaces at the beginning of a line with tabs.
3. Press Esc, type :wq!, and press Enter to save the file and exit.
See 6 to perform compilation and installation.
```
make all
```

Parent topic: (Optional) Extended Installation