doc: delete useless parameters and update doc of MD

Author: YuLiu98

doc/examples/md.md

@@ -37,8 +37,7 @@ md_type           1    //choose ensemble
 md_dt               1    //time step
 md_tfirst           700  //the first target temperature
 md_restart            0    //whether restart md
-md_qmass            1    //mass of themostat
-md_dumpfred       10   //The period to dump MD information for monitoring and restarting MD
+md_dumpfreq       10   //The period to dump MD information
 ```
 
 These MD parameters means that ABACUS will use NVT ensemble with Nosé-hoover themostat; the time step is 1fs, and target temperature is 700K; start renew without restart file, set the mass of themostat as 1g/mol, and calculate the MSD and diffusion coefficent from first step.
@@ -47,10 +46,9 @@ Note: *Please turn off symmetry when do MD simulation.*
 
 - md_type : -1, FIRE; 0, NVE; 1, NHC; 2, LGV; 3, ADS; 4, MSST
 - md_dt : time step in md simulation (fs)
-- md_tfirst : target temperature in md simulation(K), you should set parameter md_tlast and md_fixtemperature when you want to change temperature during md simulation.
+- md_tfirst : target temperature in md simulation(K), you should set parameter md_tlast when you want to change temperature during md simulation.
 - md_restart : 0, no need of restart ; 1, restart with restart file, you must repalce STRU file with STRU_MD before you run the restart task.
-- md_qmass : mass of thermostat, set by experience, if you don’t know how to set, set it to 0 will have a number autosetted by ABACUS
-- md_dumpfred : frequency for output consequence of md simulation
+- md_dumpfreq : frequency for output consequence of md simulation
 
 The STRU file is:
 ```
@@ -149,9 +147,9 @@ Gamma
 ```
 
 Run the program, and see results in the output directory. The following files are about MD:
-- md_pos_$num.cif optimized structure in direct coordinate
-- MD_RESTART output the information of md for restart
-- STRU_MD if you want to restart md, you must replace the STRU with this file.
+- STRU_MD_$num: optimized structures in direct coordinate
+- Restart_md.dat: output the information of md for restart
+- If you want to restart md, you must replace the STRU with STRU_MD_$num.
 
 MD information can be found in file running_md.log or in file MD_OUT
 

doc/examples/tddft.md

@@ -28,17 +28,9 @@ dr2 1.0e-6
 md_type 0
 md_dt 0.01
 md_tfirst 30
-md_mdoutpath mdtest
 md_restart 0
-md_fixtemperature 20000
-md_nresn 3
-md_nyosh 3
-md_qmass 0
 md_tlast 30
-md_dumpfred 1
-md_domsd 0
-md_domsdatom 0
-md_outputstressperiod 0
+md_dumpfreq 1
 tddft 1
 set_vel 1
 ocp 1