add README in tests

Author: mohanchen

tests/README

@@ -0,0 +1,128 @@
+--------------------------------------
+ Purposes for this test directory is:
+--------------------------------------
+1,  cover most features of ABACUS
+2,  autotest script to check if the version is correct.
+    (reference result calculated by one core and saved in result.ref)
+    (user can change NUMBEROFPROCESS value in integrate/general_info to test by multi cores)
+
+--------------------------------------
+ Folders in this directory
+--------------------------------------
+01_PW: KSDFT calculations in PW basis with multple k-point setting.
+02_NAO_Gamma: KSDFT calculations in NAO basis with gamma-only k-point setting.
+03_NAO_multik: KSDFT calculations in NAO basis with multiple k-point setting.
+04_LJ_DP: Lennard-Jones potentials and Deep Potentials.
+05_rtTDDFT: Real-time TDDFT tests.
+06_SDFT: Stochastic DFT tests.
+07_OFDFT: Orbital-free DFT tests.
+08_EXX: Hybrid functional and LR-TDDFT tests.
+09_DeePKS: DeePKS tests.
+10_others: Other tests such as LCAO in pw.
+11_PW_GPU: KSDFT calculations in PW basis with multple k-point setting using GPU.
+12_NAO_Gamma_GPU: KSDFT calculations in NAO basis with gamma-only k-point setting using GPU.
+13_NAO_multik_GPU: KSDFT calculations in NAO basis with multiple k-point setting using GPU.
+15_rtTDDFT_GPU: Real-time TDDFT tests using LCAO basis running on GPU.
+16_SDFT_GPU: Integrate tests for stochastic DFT running on GPU. 
+CMakeLists.txt: Cmake file for this directory.
+integrate: Store acripts for integrte tests.
+libxc: Examples related to LibXC, will be refactored soon.
+performance: Examples related to performance of ABACUS, will be refactored soon.
+PP_ORB: Collection of all the used pseudopotentials and numerical atomic orbitals.
+README: This file
+
+
+--------------------------------------
+ How to run tests
+--------------------------------------
+
+1. Modify the file '/integrate/general_info' and set appropriate parameters.
+2. Set the appropriate 'abacus' in the Autotst.sh.
+3. Enter each integrate test directory, try this script for autotests
+../integrate/Autotest.sh
+4. if you want to focus on No.xxx example, such as 101_PW_OU:
+cd 101_PW_OU and then type
+./../integrate/Single.sh $parameter
+# you can choose $parameter among "" (empty), debug or ref
+# 'ref': generate result.ref file (the answer you need)
+
+
+--------------------------------------
+ Some comman names appear in the tests 
+--------------------------------------
+_PW    plain wave bases
+_NO    numerical atoms orbitals bases
+_NP    expand numerical atoms orbitals in plane-wave basis
+
+_OU    old upf pseudopotential file
+_15    SG15 pseudopotential file
+_VW    vwr pseudopotential file
+_DJ    DOJO pseudopotential file
+
+_FD    smearing methodL Fermi-dirac
+_FX    smearing method: Fixed occupations
+_M2    smearing method: mp2
+_MP    smearing method: Methfessel-Paxton (MP)
+_MV    smearing method: Marzari-Vanderbilt
+_SG    smearing method: Gaussian
+
+_SY    turn on symmetry
+_CG    cg diagonalization method
+_DA    david diagonalization method
+
+_S1    one spin channel
+_S2    two spin channels
+_S4    four spin channels
+
+_GE    genelpa diagonalization method
+_SC    scalapack diagonalization method
+
+_RE    relax calculation
+_CR    cell-relax calculation
+_CF    calculate and output force
+_CS    calculate and output stress
+_MD    molecular dynamics
+_TD    real-time TDDFT
+_LR    linear response TDDFT
+
+_OH    output Halmitonian matrix
+_OB    output bands file
+_OD    output DOS file
+_OW    output wave functions
+_OC    output charge density
+_OK    output kinetic energy density
+
+_GO    gamma_only method
+_KP    all K-Points method
+
+_FM    ferromagnetic nspin=2
+_AF    anti-ferromagnetic nspin=2 anti initial magnetism
+
+_PU    DFT plus U
+_BS    BSSE
+
+_PL    mixing_type plain mixing
+_KK    mixing_type kerker mixing
+_PU    mixing_type pulay mixing
+_PK    mixing_type pulay-kerker mixing
+_BD    mixing_type broyden mixing
+
+_SO    spin orbit coupling (SOC)
+
+_XX    EXX
+_VD    VDW (both d2 or d3)
+
+_MG    move ions method: cg
+_MF    move ions method: FIRE
+_MB    move ions method: bfgs
+_MT    move ions method: bfgs_traj
+
+_1O    first-order charge extrapolation
+_2O    second-order charge extrapolation
+
+Orbital free DFT properties
+
+_OF    orbital free density functional theory (OFDFT)
+_OP    optimization method used in OFDFT
+_KE    kinetic energy functional used in OFDFT
+_CO    convergence check