Load Project and Fit: LBCO, HRPT¶

This is the most minimal example of using EasyDiffraction. It shows how to load a previously saved project from a directory and run refinement — all in just a few lines of code.

For this example, constant-wavelength neutron powder diffraction data for La0.5Ba0.5CoO3 from HRPT at PSI is used.

It does not contain any advanced features or options, and includes no comments or explanations — these can be found in the other tutorials.

🛠️ Import Library¶

In [2]:

from easydiffraction import Project
from easydiffraction import download_data

from easydiffraction import Project from easydiffraction import download_data

📂 Load Project¶

Download Project¶

In [3]:

project_dir = download_data(id=36, destination='projects')

project_dir = download_data(id=36, destination='projects')

Getting data...

Data #36: La0.5Ba0.5CoO3, HRPT (PSI), 300 K

✅ Data #36 downloaded and extracted to '../../../projects/ed-36/lbco_hrpt'

Load Project¶

In [4]:

project = Project.load(project_dir)

project = Project.load(project_dir)

🚀 Perform Analysis¶

Display Structure¶

In [5]:

project.display.structure(struct_name='lbco')

project.display.structure(struct_name='lbco')

Structure 🧩 'lbco' (Atom view type: 'covalent')

Loading plot…

drag = rotate
wheel = zoom
right-drag = pan

Run Fitting¶

In [6]:

project.analysis.fit()

project.analysis.fit()

Standard fitting

📋 Using experiment 🔬 'hrpt' for 'single' fitting

🚀 Starting fit process with 'lmfit (leastsq)'...

📈 Goodness-of-fit progress:

	iteration	time (s)	χ²	change / status
1	1	0.30	1.29
2	68	3.78	1.29

🏆 Best goodness-of-fit (reduced χ²) is 1.29 at iteration 67

✅ Fitting complete.

Saving project 📦 'lbco_hrpt' to '../../../projects/ed-36/lbco_hrpt'

├── 📄 project.cif

├── 📁 structures/

│   └── 📄 lbco.cif

├── 📁 experiments/

│   └── 📄 hrpt.cif

├── 📁 analysis/

│   └── 📄 analysis.cif

└── 📁 reports/

    └── 📄 lbco_hrpt.html

Display Fit Results¶

In [7]:

project.display.fit.results()

project.display.fit.results()

⚙️ Settings used:

	Name	Value	Description
1	max_iterations	1000	Maximum solver iterations.

📋 Least-squares fit results:

	Metric	Value
1	🧪 Minimizer	lmfit (leastsq)
2	✅ Overall status	success
3	⏱️ Fitting time (seconds)	3.78
4	🔁 Iterations	65
5	📏 Goodness-of-fit (reduced χ²)	1.29
6	📏 R-factor (Rf, %)	5.63
7	📏 R-factor squared (Rf², %)	5.27
8	📏 Weighted R-factor (wR, %)	4.41

📈 Refined parameters:

	datablock	category	entry	parameter	units	start	value	s.u.	change
1	lbco	cell		length_a	Å	3.8908	3.8909	0.0000	0.00 % ↑
2	lbco	atom_site	La	adp_iso	Ų	0.5150	0.5051	0.0278	1.93 % ↓
3	lbco	atom_site	Co	adp_iso	Ų	0.2190	0.2370	0.0564	8.22 % ↑
4	lbco	atom_site	O	adp_iso	Ų	1.3920	1.3935	0.0160	0.11 % ↑
5	hrpt	linked_phases	lbco	scale		9.1440	9.1351	0.0538	0.10 % ↓
6	hrpt	peak		broad_gauss_u	deg²	0.0817	0.0816	0.0031	0.16 % ↓
7	hrpt	peak		broad_gauss_v	deg²	-0.1164	-0.1159	0.0066	0.41 % ↓
8	hrpt	peak		broad_gauss_w	deg²	0.1205	0.1204	0.0032	0.04 % ↓
9	hrpt	peak		broad_lorentz_y	deg	0.0847	0.0844	0.0021	0.30 % ↓
10	hrpt	instrument		twotheta_offset	deg	0.6204	0.6226	0.0010	0.35 % ↑
11	hrpt	background	1	y		169.7000	168.5585	1.3669	0.67 % ↓
12	hrpt	background	2	y		164.8000	164.3357	0.9990	0.28 % ↓
13	hrpt	background	3	y		167.0200	166.8881	0.7386	0.08 % ↓
14	hrpt	background	4	y		175.2700	175.4005	0.6488	0.07 % ↑
15	hrpt	background	5	y		175.1200	174.2812	0.8944	0.48 % ↓

• start = parameter value before refinement
• value = refined value from least-squares minimization
• s.u. = standard uncertainty (one sigma), from the covariance matrix
• change = relative change from start, in %; ↑ = increase, ↓ = decrease

In [8]:

project.display.fit.correlations()

project.display.fit.correlations()

Loading plot…

In [9]:

project.display.pattern(expt_name='hrpt')

project.display.pattern(expt_name='hrpt')

Loading plot…

💾 Save Project¶

In [10]:

project.save_as(dir_path='projects/ed_18_lbco_hrpt')

project.save_as(dir_path='projects/ed_18_lbco_hrpt')

Saving project 📦 'lbco_hrpt' to '../../../projects/ed_18_lbco_hrpt'

├── 📄 project.cif

├── 📁 structures/

│   └── 📄 lbco.cif

├── 📁 experiments/

│   └── 📄 hrpt.cif

├── 📁 analysis/

│   └── 📄 analysis.cif

└── 📁 reports/

    └── 📄 lbco_hrpt.html