Force Loss Convergence

[caolz]

I am training a model using the "se_a" type.
{
"_comment": " model parameters",
"model": {
"type_map": ["Au"],
"descriptor" :{
"type": "se_a",
"sel": [25],
"rcut_smth": 5.80,
"rcut": 6.00,
"neuron": [25, 50, 100],
"resnet_dt": false,
"axis_neuron": 12,
"seed": 3246556277,
"_comment": " that's all"
},
"fitting_net" : {
"neuron": [240, 240, 240],
"resnet_dt": true,
"seed": 1978363284,
"_comment": " that's all"
},
"_comment": " that's all"
},

"learning_rate" :{
"type":		"exp",
"decay_steps":	5000,
"start_lr":	0.001,	
"stop_lr":	3.51e-8,
"_comment":	"that's all"
},

"loss" :{
"start_pref_e": 0.05,
"limit_pref_e":	1,
"start_pref_f":	1000,
"limit_pref_f":	1,
"start_pref_v":	0,
"limit_pref_v":	0,
"_comment":	" that's all"
},

"_comment": " traing controls",
"training" : {
"systems":	["../1-data/Au16", "../1-data/Au17", "../1-data/Au18", "../1-data/Au19", "../1-data/Au20", "../1-data/Au21", "../1-data/Au22", "../1-data/Au23", "../1-data/Au24", "../1-data/Au25"],
"set_prefix":	"set",    
"stop_batch":	1000000,
"batch_size":	"auto",

"seed":		2662107775,

"_comment": " display and restart",
"_comment": " frequencies counted in batch",
"disp_file":	"lcurve.out",
"disp_freq":	100,
"numb_test":	10,
"save_freq":	1000,
"save_ckpt":	"model.ckpt",
"load_ckpt":	"model.ckpt",
"disp_training":true,
"time_training":true,
"profiling":	false,
"profiling_file":"timeline.json",
"_comment":	"that's all"
},

"_comment":		"that's all"

}
I only modify sel, it has been changed 6 times, which are 25,100,233,500,800,1000.
I drew the Loss of energy and force respectively.

sel = 25

sel = 100

sel = 233

sel = 500

sel = 800

sel = 1000

How can I solve it?

[njzjz]

You may check your data - I guess it's very likely to be incorrect. The energy and force seem to be inconsistent.

[caolz]

Can you help me check if my unit conversion is wrong? I extracted data from DMol3. The energy unit is 1 Ha = 27.2114 eV, the coordinate unit is 1 a.u. = 0.529177249 Angstrom, and the force unit is 1 Ha/Bohr = 51.42208619083232 eV/Angstrom. Do I need to use scientific notation after conversion?

[njzjz]

Did you use negative energy derivative？ Force is a negative gradient of the potential energy.

[caolz]

As you can see, starting from the third row and third column, I extract the coordinates and force, and convert the units.

[njzjz]

The third column is energy derivatives but not forces. Force is the negative energy derivative.

[caolz]

Thank you for your help!