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- added 2 oso examples in examples/SPIN/spinmin
- added doc for oso_cg and oso_lbfgs
This commit is contained in:
julient31
2019-07-23 09:27:15 -06:00
parent a9a2c7a496
commit f0679cff6d
12 changed files with 200 additions and 32 deletions
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1
doc/src/lammps.book
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@ -647,6 +647,7 @@ pair_sph_lj.html
pair_sph_rhosum.html
pair_sph_taitwater.html
pair_sph_taitwater_morris.html
pair_spin_dipole.html
pair_spin_dmi.html
pair_spin_exchange.html
pair_spin_magelec.html

22
doc/src/min_modify.txt
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@ -13,11 +13,11 @@ min_modify command :h3
min_modify keyword values ... :pre
one or more keyword/value pairs may be listed :ulb,l
keyword = {dmax} or {line} or {alpha_damp} or {discrete_factor}
keyword = {dmax} or {line} or {alpha_damp} or {discrete_factor} or {spin_cubic} or {spin_none}
{dmax} value = max
max = maximum distance for line search to move (distance units)
{line} value = {backtrack} or {quadratic} or {forcezero}
backtrack,quadratic,forcezero = style of linesearch to use
{line} value = {backtrack} or {quadratic} or {forcezero} or {spin_cubic} or {spin_none}
backtrack,quadratic,forcezero,spin_cubic,spin_none = style of linesearch to use
{alpha_damp} value = damping
damping = fictitious Gilbert damping for spin minimization (adim)
{discrete_factor} value = factor
@ -80,7 +80,21 @@ See "min_spin"_min_spin.html for more information about those
quantities.
Default values are {alpha_damp} = 1.0 and {discrete_factor} = 10.0.
[Restrictions:] none
The choice of a line search algorithm for the {spin_oso_cg} and
{spin_oso_lbfgs} can be specified via the {line} keyword.
The {spin_cubic} and {spin_none} only make sense when those two
when one of those two minimization styles is declared.
The {spin_cubic} keyword activates the line search procedure when
the {spin_oso_cg} algorithm is used.
The {spin_none} keyword deactivates the line search procedure when
the {spin_oso_lbfgs} algorithm is used.
[Restrictions:] The line search procedure of styles
{spin_oso_cg} and {spin_oso_lbfgs} cannot be used for magnetic
NEB calculations. See "neb/spin"_neb_spin.html for more
explanation.
[Related commands:]

36
doc/src/min_spin.txt
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@ -6,14 +6,19 @@
:line
min_style spin command :h3
min_style spin_oso_cg command :h3
min_style spin_oso_lbfgs command :h3
[Syntax:]
min_style spin :pre
min_style spin
min_style spin_oso_cg
min_style spin_oso_lbfgs :pre
[Examples:]
min_style spin :pre
min_style spin_oso_lbfgs
min_modify discrete_factor 10.0 line_search 0 :pre
[Description:]
@ -46,9 +51,29 @@ definition of this timestep.
{discrete_factor} can be defined with the "min_modify"_min_modify.html
command.
NOTE: The {spin} style replaces the force tolerance by a torque
Style {spin_oso_cg} defines an orthogonal spin optimization
(OSO) combined to a conjugate gradient (CG) algorithm.
The "min_modify"_min_modify.html command can be used to
couple the {spin_oso_cg} to a line search procedure, and to modify the
discretization factor {discrete_factor}.
Style {spin_oso_lbfgs} defines an orthogonal spin optimization
(OSO) combined to a limited-memory Broyden-Fletcher-Goldfarb-Shanno
(LBFGS) algorithm.
By default, style {spin_oso_lbfgs} uses a line search procedure.
The "min_modify"_min_modify.html command can be used to
deactivate the line search procedure.
For more information about styles {spin_oso_cg} and {spin_oso_lbfgs},
see their implementation reported in "(Ivanov)"_#Ivanov1.
NOTE: All the {spin} styles replace the force tolerance by a torque
tolerance. See "minimize"_minimize.html for more explanation.
NOTE: The {spin_oso_cg} and {spin_oso_lbfgs} styles can be used
for magnetic NEB calculations only if the line search procedure
is deactivated. See "neb/spin"_neb_spin.html for more explanation.
[Restrictions:]
This minimization procedure is only applied to spin degrees of
@ -63,3 +88,8 @@ freedom for a frozen lattice configuration.
The option defaults are {alpha_damp} = 1.0 and {discrete_factor} =
10.0.
:line
:link(Ivanov1)
[(Ivanov)] Ivanov, Uzdin, Jonsson. arXiv preprint arXiv:1904.02669, (2019).

19
doc/src/min_style.txt
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@ -11,7 +11,8 @@ min_style command :h3
min_style style :pre
style = {cg} or {hftn} or {sd} or {quickmin} or {fire} or {spin} :ul
style = {cg} or {hftn} or {sd} or {quickmin} or {fire} or {spin}
or {spin_oso_cg} or {spin_oso_lbfgs} :ul
[Examples:]
@ -64,11 +65,25 @@ a minimization.
Style {spin} is a damped spin dynamics with an adaptive
timestep.
See the "min/spin"_min_spin.html doc page for more information.
Style {spin_oso_cg} uses an orthogonal spin optimization (OSO)
combined to a conjugate gradient (CG) approach to minimize spin
configurations.
Style {spin_oso_lbfgs} uses an orthogonal spin optimization (OSO)
combined to a limited-memory Broyden-Fletcher-Goldfarb-Shanno
(LBFGS) approach to minimize spin configurations.
See the "min/spin"_min_spin.html doc page for more information
about the {spin}, {spin_oso_cg} and {spin_oso_lbfgs} styles.
Either the {quickmin} and {fire} styles are useful in the context of
nudged elastic band (NEB) calculations via the "neb"_neb.html command.
Either the {spin}, {spin_oso_cg} and {spin_oso_lbfgs} styles are useful
in the context of magnetic geodesic nudged elastic band (GNEB) calculations
via the "neb/spin"_neb_spin.html command.
NOTE: The damped dynamic minimizers use whatever timestep you have
defined via the "timestep"_timestep.html command. Often they will
converge more quickly if you use a timestep about 10x larger than you

3
doc/src/minimize.txt
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@ -103,7 +103,8 @@ the line search fails because the step distance backtracks to 0.0
the number of outer iterations or timesteps exceeds {maxiter}
the number of total force evaluations exceeds {maxeval} :ul
NOTE: the "minimization style"_min_style.html {spin} replaces
NOTE: the "minimization style"_min_style.html {spin},
{spin_oso_cg}, and {spin_oso_lbfgs} replace
the force tolerance {ftol} by a torque tolerance.
The minimization procedure stops if the 2-norm (length) of the
global torque vector (defined as the cross product between the

6
doc/src/neb_spin.txt
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@ -172,7 +172,8 @@ command is issued.
A NEB calculation proceeds in two stages, each of which is a
minimization procedure, performed via damped dynamics. To enable
this, you must first define a damped spin dynamics
"min_style"_min_style.html, using the {spin} style (see
"min_style"_min_style.html, using either the {spin},
{spin_oso_cg}, or {spin_oso_lbfgs} style (see
"min_spin"_min_spin.html for more information).
The other styles cannot be used, since they relax the lattice
degrees of freedom instead of the spins.
@ -358,6 +359,9 @@ This command can only be used if LAMMPS was built with the SPIN
package. See the "Build package"_Build_package.html doc
page for more info.
The line search procedures of the {spin_oso_cg} and {spin_oso_lbfgs}
minimization styles cannot be used in a GNEB calculation.
:line
[Related commands:]

5
doc/src/pair_spin_dipole.txt
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@ -25,9 +25,8 @@ pair_coeff * * 10.0
pair_coeff 2 3 8.0 :pre
pair_style spin/dipole/long 9.0
pair_coeff * * 1.0 1.0
pair_coeff 2 3 1.0 1.0 2.5 4.0 scale 0.5
pair_coeff 2 3 1.0 1.0 2.5 4.0 :pre
pair_coeff * * 10.0
pair_coeff 2 3 6.0 :pre
[Description:]

54
examples/SPIN/spinmin/in.spinmin_cg.bfo Normal file
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@ -0,0 +1,54 @@
# bfo in a 3d periodic box
units metal
dimension 3
boundary p p f
atom_style spin
# necessary for the serial algorithm (sametag)
atom_modify map array
lattice sc 3.96
region box block 0.0 34.0 0.0 34.0 0.0 1.0
create_box 1 box
create_atoms 1 box
# setting mass, mag. moments, and interactions for bcc iron
mass 1 1.0
set group all spin/random 11 2.50
pair_style hybrid/overlay spin/exchange 6.0 spin/magelec 4.5 spin/dmi 4.5
pair_coeff * * spin/exchange exchange 6.0 -0.01575 0.0 1.965
# pair_coeff * * spin/magelec magelec 4.5 0.000109 1.0 1.0 1.0
pair_coeff * * spin/magelec magelec 4.5 0.00109 1.0 1.0 1.0
pair_coeff * * spin/dmi dmi 4.5 0.00005 1.0 1.0 1.0
neighbor 0.1 bin
neigh_modify every 10 check yes delay 20
fix 1 all precession/spin anisotropy 0.0000033 0.0 0.0 1.0
fix_modify 1 energy yes
timestep 0.0001
compute out_mag all spin
compute out_pe all pe
compute out_ke all ke
compute out_temp all temp
variable magz equal c_out_mag[3]
variable magnorm equal c_out_mag[4]
variable emag equal c_out_mag[5]
variable tmag equal c_out_mag[6]
thermo 50
thermo_style custom step time v_magnorm v_emag v_tmag temp etotal
thermo_modify format float %20.15g
compute outsp all property/atom spx spy spz sp fmx fmy fmz
dump 1 all custom 50 dump.lammpstrj type x y z c_outsp[1] c_outsp[2] c_outsp[3] c_outsp[4] c_outsp[5] c_outsp[6] c_outsp[7]
min_style spin/oso_cg
min_modify discrete_factor 10.0 line_search 0
minimize 1.0e-10 1.0e-10 10000 1000

54
examples/SPIN/spinmin/in.spinmin_lbfgs.bfo Normal file
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@ -0,0 +1,54 @@
# bfo in a 3d periodic box
units metal
dimension 3
boundary p p f
atom_style spin
# necessary for the serial algorithm (sametag)
atom_modify map array
lattice sc 3.96
region box block 0.0 34.0 0.0 34.0 0.0 1.0
create_box 1 box
create_atoms 1 box
# setting mass, mag. moments, and interactions for bcc iron
mass 1 1.0
set group all spin/random 11 2.50
pair_style hybrid/overlay spin/exchange 6.0 spin/magelec 4.5 spin/dmi 4.5
pair_coeff * * spin/exchange exchange 6.0 -0.01575 0.0 1.965
#pair_coeff * * spin/magelec magelec 4.5 0.000109 1.0 1.0 1.0
pair_coeff * * spin/magelec magelec 4.5 0.00109 1.0 1.0 1.0
pair_coeff * * spin/dmi dmi 4.5 0.00005 1.0 1.0 1.0
neighbor 0.1 bin
neigh_modify every 10 check yes delay 20
fix 1 all precession/spin anisotropy 0.0000033 0.0 0.0 1.0
fix_modify 1 energy yes
timestep 0.0001
compute out_mag all spin
compute out_pe all pe
compute out_ke all ke
compute out_temp all temp
variable magz equal c_out_mag[3]
variable magnorm equal c_out_mag[4]
variable emag equal c_out_mag[5]
variable tmag equal c_out_mag[6]
thermo 50
thermo_style custom step time v_magnorm v_emag v_tmag temp etotal
thermo_modify format float %20.15g
compute outsp all property/atom spx spy spz sp fmx fmy fmz
dump 1 all custom 50 dump.lammpstrj type x y z c_outsp[1] c_outsp[2] c_outsp[3] c_outsp[4] c_outsp[5] c_outsp[6] c_outsp[7]
min_style spin/oso_lbfgs
min_modify discrete_factor 10.0 line_search 1
minimize 1.0e-15 1.0e-10 10000 1000

4
src/SPIN/min_spin.cpp
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@ -80,12 +80,12 @@ void MinSpin::setup_style()
int MinSpin::modify_param(int narg, char **arg)
{
if (strcmp(arg[0],"alpha_damp") == 0) {
if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
if (narg < 2) error->all(FLERR,"Illegal min_modify command");
alpha_damp = force->numeric(FLERR,arg[1]);
return 2;
}
if (strcmp(arg[0],"discrete_factor") == 0) {
if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
if (narg < 2) error->all(FLERR,"Illegal min_modify command");
discrete_factor = force->numeric(FLERR,arg[1]);
return 2;
}

10
src/SPIN/min_spin_oso_cg.cpp
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@ -133,12 +133,10 @@ void MinSpinOSO_CG::setup_style()
int MinSpinOSO_CG::modify_param(int narg, char **arg)
{
if (strcmp(arg[0],"line_search") == 0) {
if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
if (narg < 2) error->all(FLERR,"Illegal min_modify command");
use_line_search = force->numeric(FLERR,arg[1]);
if (nreplica > 1 && use_line_search)
error->all(FLERR,"Illegal fix_modify command, cannot use NEB and line search together");
return 2;
}
if (strcmp(arg[0],"discrete_factor") == 0) {
@ -250,9 +248,9 @@ int MinSpinOSO_CG::iterate(int maxiter)
neval++;
}
//// energy tolerance criterion
//// only check after DELAYSTEP elapsed since velocties reset to 0
//// sync across replicas if running multi-replica minimization
// energy tolerance criterion
// only check after DELAYSTEP elapsed since velocties reset to 0
// sync across replicas if running multi-replica minimization
if (update->etol > 0.0 && ntimestep-last_negative > DELAYSTEP) {
if (update->multireplica == 0) {

14
src/SPIN/min_spin_oso_lbfgs.cpp
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@ -145,16 +145,14 @@ int MinSpinOSO_LBFGS::modify_param(int narg, char **arg)
{
if (strcmp(arg[0],"line_search") == 0) {
if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
if (narg < 2) error->all(FLERR,"Illegal min_modify command");
use_line_search = force->numeric(FLERR,arg[1]);
if (nreplica > 1 && use_line_search)
error->all(FLERR,"Illegal fix_modify command, cannot use NEB and line search together");
error->all(FLERR,"Illegal min_modify command, cannot use NEB and line search together");
return 2;
}
if (strcmp(arg[0],"discrete_factor") == 0) {
if (narg < 2) error->all(FLERR,"Illegal fix_modify command");
if (narg < 2) error->all(FLERR,"Illegal min_modify command");
double discrete_factor;
discrete_factor = force->numeric(FLERR,arg[1]);
maxepsrot = MY_2PI / (10 * discrete_factor);
@ -266,9 +264,9 @@ int MinSpinOSO_LBFGS::iterate(int maxiter)
neval++;
}
//// energy tolerance criterion
//// only check after DELAYSTEP elapsed since velocties reset to 0
//// sync across replicas if running multi-replica minimization
// energy tolerance criterion
// only check after DELAYSTEP elapsed since velocties reset to 0
// sync across replicas if running multi-replica minimization
if (update->etol > 0.0 && ntimestep-last_negative > DELAYSTEP) {
if (update->multireplica == 0) {