用Quantum ESPRESSO计算声子的时候，不知道什么原因，算了大概半个月，作业就中断了。这时候已经计算了一些波矢的振动频率，重新计算这些太浪费时间了。ph.x有计算指定声子的功能，所以可以续算。

续算的步骤：

1. 计算phonon需要电子自洽计算的信息，所以首先要在当前目录提交一个scf的任务。其中ph.x的输入文件中要加上recover=.true. 输出文件包括output_0文件夹，P0.scf.out和P0.dyn0

#!/bin/bash
#PBS -N titanite-ph
#PBS -l nodes=node06:ppn=16
#PBS -l walltime=3000:00:00
#PBS -e error
#PBS -o OUT
cd /home/zhch/espresso/titanite/phonon/dyn5
EXEDIR=/opt/software/espresso-5.2.0/bin
for pres in 0
do
toutput=/home/zhch/espresso/titanite/phonon/dyn5/output_$pres
mkdir -p $toutput

cat>P$pres.scf.in<<EOF
&CONTROL
calculation=‘scf‘,
outdir=‘$toutput‘,
pseudo_dir=‘/home/zhch/espresso/pseudo‘,
forc_conv_thr=1.0d-4,
dt=30,
nstep=500,
tstress=.true.
prefix=‘titanite‘,
tprnfor=.true.
restart_mode =‘from_scratch‘
/
&SYSTEM
ibrav=0,
ntyp=4,
nat=32,
ecutwfc=70.0,
/
&ELECTRONS
mixing_beta = 0.7,
conv_thr = 1.0d-8,
/

ATOMIC_SPECIES
Ca 40.078 Ca-sp4.vdb
Si 28.085 Si.rw2
Ti 47.867 Ti.pz-sp-van.UPF
O 15.999 O.rw2

CELL_PARAMETERS (angstrom)
6.504369409 0.004238976 0.000000000
-2.804707609 6.385043964 -0.000000000
0.000000000 -0.000000000 8.653731229

ATOMIC_POSITIONS (crystal)
Ca 0.750074069 0.249620897 0.080347226
Ca 0.249925931 0.750379117 0.919652767
Ca 0.249925946 0.250379117 0.580347233
Ca 0.750074069 0.749620883 0.419652767
Ti 0.249939521 0.500233385 0.249905695
Ti 0.750060449 0.499766615 0.750094290
Ti 0.249939521 0.000233367 0.250094319
Ti 0.750060449 0.999766615 0.749905710
Si 0.250080601 0.250074335 0.932255702
Si 0.749919399 0.749925665 0.067744298
Si 0.749919399 0.249925665 0.432255672
Si 0.250080601 0.750074335 0.567744357
O 0.249822264 0.750068377 0.180887366
O 0.750177706 0.249931623 0.819112604
O 0.249822264 0.250068392 0.319112634
O 0.750177706 0.749931623 0.680887396
O 0.063556361 0.086929055 0.815781937
O 0.936443654 0.913070922 0.184218063
O 0.063556361 0.586929078 0.684218063
O 0.936443654 0.413070922 0.315781937
O 0.147664700 0.384935872 0.038739981
O 0.852335285 0.615064158 0.961260011
O 0.147664700 0.884935902 0.461260011
O 0.852335285 0.115064098 0.538739989
O 0.563341198 0.086967448 0.315745038
O 0.436658802 0.913032530 0.684254962
O 0.563341198 0.586967470 0.184254977
O 0.436658802 0.413032530 0.815745038
O 0.352459090 0.615277747 0.461158719
O 0.647540940 0.384722253 0.538841281
O 0.352459090 0.115277718 0.038841277
O 0.647540940 0.884722253 0.961158719

K_POINTS {automatic}
4 4 4 0 0 0
EOF
mpirun -np 16 $EXEDIR/pw.x < P$pres.scf.in > P$pres.scf.out

cat>P$pres.ph.in<< EOF
titanite
&inputph
tr2_ph=1.0d-14
prefix=‘titanite‘
epsil=.true.
ldisp=.true.
recover=.true.
nq1=2,nq2=2,nq3=2
amass(1)=40.078
amass(2)=28.085
amass(3)=47.867
amass(4)=15.999
outdir=‘$toutput‘
fildyn=‘P$pres.dyn‘
/
EOF
mpirun -np 16 $EXEDIR/ph.x < P$pres.ph.in > P$pres.ph.out
done

2. 指定q点计算频率

#!/bin/bash
#PBS -N titanite-ph
#PBS -l nodes=node06:ppn=16
#PBS -l walltime=3000:00:00
#PBS -e error
#PBS -o OUT
cd /home/zhch/espresso/titanite/phonon/dyn5
EXEDIR=/opt/software/espresso-5.2.0/bin
for pres in 0
do
toutput=/home/zhch/espresso/titanite/phonon/dyn5/output_$pres
mkdir -p $toutput

cat>P$pres.ph.in<< EOF
titanite
&inputph
tr2_ph=1.0d-14
prefix=‘titanite‘
epsil=.true.
ldisp=.true.
nq1=2,nq2=2,nq3=2
start_q=5
last_q=8
amass(1)=40.078
amass(2)=28.085
amass(3)=47.867
amass(4)=15.999
outdir=‘$toutput‘
fildyn=‘P$pres.dyn‘
/
EOF
mpirun -np 16 $EXEDIR/ph.x < P$pres.ph.in > P$pres.ph.out
done

QE DFPT续算