Mursit-Large-TR-Retrieval is a large-scale Turkish embedding model pre-trained entirely from scratch on Turkish-dominant corpora and fine-tuned for retrieval tasks. The model is based on ModernBERT-large architecture (403M parameters) and optimized specifically for Turkish legal domain applications. This model achieves strong performance on Turkish retrieval benchmarks with 56.87 MTEB Score and 46.56 Legal Score, ranking among the top Turkish embedding models.
Key Features:
Pre-trained from scratch on approximately 112.7 billion tokens of Turkish-dominant corpus
Post-trained for embedding tasks using contrastive learning on MS MARCO-TR dataset
Achieves strong performance on Turkish legal retrieval benchmarks
Optimized for Turkish legal domain with custom tokenizer trained on legal documents
Model Type: Embedding Parameters: 403M Base Model: newmindai/Mursit-Large Architecture: ModernBERT-large Embedding Dimension: 1,024 Max Sequence Length: 2,048 tokens
Architecture Details
The model is based on ModernBERT-large architecture:
Attention Mechanism: Alternating local and global attention
Normalization: Pre-layer normalization with RMSNorm
Activation: GeGLU (Gated Linear Units with GELU) in MLP layers
Position Embeddings: Rotary positional embeddings (RoPE) with θ=20,000
Context Length: 2,048 tokens
Layers: 28 transformer layers
Hidden Size: 1,024
FFN Size: 2,624
Attention Heads: 16 heads with 64 dimensions each
Window Size: 128 (for sliding window attention in local layers)
Vocabulary Size: 59,008 tokens
Training Details
Pre-training:
Dataset: Turkish-dominant corpus totaling approximately 112.7 billion tokens
Legal Sources:
Court of Cassation (Yargıtay): 10.3M sequences, ~3.43B tokens
Council of State (Danıştay): 151K sequences, ~0.11B tokens
The following visualization shows the model's performance compared to other Turkish language models:
Model Performance Comparison
Model Performance Comparison: Legal Score vs. MTEB Score. Embedding models (green triangles) show superior performance compared to MLM models. Mursit-Large-TR-Retrieval achieves strong performance with 56.87 MTEB Score and 46.56 Legal Score, ranking among the top Turkish embedding models.
This model was evaluated on the comprehensive MTEB-Turkish benchmark, which includes 17 tasks across 5 task types. The benchmark evaluates models on general Turkish NLP tasks as well as domain-specific legal retrieval tasks.
Comprehensive Benchmark Results
The following table presents comprehensive evaluation results across all models evaluated on the MTEB-Turkish benchmark. This model's results are highlighted in italics.
Model
MTEB
Legal
Cls.
Clus.
Pair
Ret.
STS
Cont.
Reg.
Case
Params
Type
embeddinggemma-300m
65.42
50.63
77.74
45.05
80.02
55.06
69.22
83.97
39.56
28.38
307M
Emb.
bge-m3
62.87
51.16
75.35
35.86
78.88
54.42
69.83
86.08
38.09
29.3
567M
Emb.
Mursit-Embed-Qwen3-1.7B-TR
56.84
34.76
68.46
42.22
59.67
50.1
63.77
70.22
17.94
16.11
1.7B
CLM-E.
Mursit-Large-TR-Retrieval
56.87
46.56
67.72
41.15
59.78
51.69
64.01
81.78
32.67
25.24
403M
Emb.
Mursit-Base-TR-Retrieval
55.86
47.52
66.25
39.75
61.31
50.07
61.9
80.4
34.1
28.07
155M
Emb.
Mursit-Embed-Qwen3-4B-TR
53.65
37.0
67.29
36.68
58.36
51.12
54.77
69.25
24.21
17.56
4B
CLM-E.
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bert-base-turkish-uncased
46.23
24.94
68.05
33.81
60.44
32.01
36.85
52.47
12.05
10.29
110M
MLM
turkish-large-bert-cased
45.3
19.12
67.43
34.24
60.11
28.68
36.04
47.57
5.93
3.85
337M
MLM
bert-base-turkish-cased
45.17
24.41
66.39
35.28
60.05
30.52
33.62
54.03
10.13
9.07
110M
MLM
BERTurk-Legal
42.02
32.63
60.61
26.24
59.51
25.8
37.94
61.4
15.51
20.99
184M
MLM
Mursit-Large
41.75
23.71
62.95
25.34
58.04
27.4
35.01
42.74
11.29
17.1
403M
MLM
turkish-base-bert-uncased
44.68
27.58
66.22
30.23
58.84
31.4
36.74
56.6
13.39
12.74
110M
MLM
Mursit-Base
40.23
17.93
59.78
25.48
58.65
20.82
36.45
36.0
7.4
10.4
155M
MLM
mmBERT-base
39.65
12.15
61.84
26.77
59.25
15.83
34.56
34.45
1.33
0.68
306M
MLM
TabiBERT
37.77
11.5
59.63
25.75
58.19
14.96
30.32
32.02
1.86
0.63
148M
MLM
ModernBERT-base
23.8
2.99
39.06
2.01
53.95
2.1
21.91
7.92
0.62
0.43
149M
MLM
ModernBERT-large
23.74
2.44
39.44
3.9
53.73
1.8
19.85
6.12
0.62
0.59
394M
MLM
Column abbreviations: MTEB = mean performance across task types; Legal = weighted average of Contracts, Regulation, Caselaw; Classification = accuracy on Turkish classification tasks; Clustering = V-measure on clustering tasks; Pair Classification = average precision on pair classification tasks like NLI; Retrieval = nDCG@10 on information retrieval tasks; Semantic Textual Similarity = Spearman correlation; Contracts = nDCG@10 on legal contract retrieval; Regulation = nDCG@10 on regulatory text retrieval; Caselaw = nDCG@10 on case law retrieval; Number of Parameters = number of model parameters; Model Type = model type (Embedding, CLM-Embedding, Masked Language Model). Bold values indicate the highest score in each column.
Key Findings:
The model achieves strong performance with 56.87 MTEB Score and 46.56 Legal Score, ranking among the top Turkish embedding models
Strong performance on Contracts retrieval (81.78 nDCG@10) demonstrates effectiveness for legal document search
Post-training on MS MARCO-TR significantly improves retrieval capabilities compared to base MLM models
Post-Training Performance Analysis
The following visualization shows the impact of post-training on retrieval performance:
Post-Training Retrieval Performance
Post-Training Retrieval Performance Comparison. Post-trained models (Mursit-Base-TR-Retrieval and Mursit-Large-TR-Retrieval) show significant improvements in legal domain retrieval tasks compared to base MLM models.
Reproducibility
To reproduce the benchmark results and training procedures for this model, please refer to:
1from sentence_transformers import SentenceTransformer
23# Load model4model = SentenceTransformer("newmindai/Mursit-Large-TR-Retrieval")56# Encode sentences7sentences =[8"Türk hukuk sistemi medeni hukuk geleneğine dayanır",9"Anayasa Türkiye Cumhuriyeti'nin temel hukuk belgesidir"10]1112embeddings = model.encode(sentences)13print(embeddings.shape)# (2, 1024)
Information Retrieval
python
1from sentence_transformers import SentenceTransformer, util
23model = SentenceTransformer("newmindai/Mursit-Large-TR-Retrieval")45query ="Sözleşme feshi nasıl yapılır?"6documents =[7"Sözleşmeler yazılı olarak feshedilebilir.",8"İş kanunu çalışma koşullarını düzenler."9]1011query_embedding = model.encode(query, convert_to_tensor=True)12doc_embeddings = model.encode(documents, convert_to_tensor=True)13scores = util.cos_sim(query_embedding, doc_embeddings)[0]1415results =[(doc, score.item())for doc, score inzip(documents, scores)]16results.sort(key=lambda x: x[1], reverse=True)1718for doc, score in results:19print(f"Score: {score:.4f} - {doc}")
ONNX Model Inference
This script demonstrates how to use the ONNX model from Hugging Face for text embedding generation.
Exporting Model to ONNX
To export the model to ONNX format, use the optimum-cli command:
1import onnxruntime as ort
2from transformers import AutoTokenizer
3from huggingface_hub import hf_hub_download
4import numpy as np
56model_id ="newmindai/Mursit-Large-TR-Retrieval"78# Load tokenizer and download ONNX model from Hugging Face9tokenizer = AutoTokenizer.from_pretrained(model_id)10onnx_path = hf_hub_download(repo_id=model_id, filename="model.onnx")1112# Use GPU if available, otherwise fallback to CPU13providers =["CUDAExecutionProvider","CPUExecutionProvider"]if"CUDAExecutionProvider"in ort.get_available_providers()else["CPUExecutionProvider"]1415sess = ort.InferenceSession(onnx_path, providers=providers)1617texts =["This is a test"]18inputs = tokenizer(texts, padding=True, truncation=True, return_tensors="np")1920outputs = sess.run(None,{21"input_ids": inputs["input_ids"].astype(np.int64),22"attention_mask": inputs["attention_mask"].astype(np.int64),23})2425embeddings = outputs[-1]# sentence_embedding is usually the last output26print(embeddings.shape)27print(embeddings[:1])
Features
Automatic GPU/CPU selection: Uses CUDA if available, otherwise falls back to CPU
Hugging Face integration: Downloads model files directly from Hugging Face Hub
Simple API: Easy-to-use interface for text embedding generation
Use Cases
Semantic search in Turkish legal documents
Legal document retrieval and ranking
Contract similarity and matching
Regulation compliance checking
Case law research and discovery
Question answering systems for legal domain
Reproducibility
To reproduce the benchmark results and training procedures for this model, please refer to:
This work was supported by the EuroHPC Joint Undertaking through project etur46 with access to the MareNostrum 5 supercomputer, hosted by Barcelona Supercomputing Center (BSC), Spain. MareNostrum 5 is owned by EuroHPC JU and operated by BSC. We are grateful to the BSC support team for their assistance with job scheduling, environment configuration, and technical guidance throughout the project.
The numerical calculations reported in this work were fully/partially performed at TÜBİTAK ULAKBİM, High Performance and Grid Computing Center (TRUBA resources). The authors gratefully acknowledge the know-how provided by the MINERVA Support for expert guidance and collaboration opportunities in HPC-AI integration.
References
If you use this model, please cite our paper:
bibtex
1@article{mecellem2026,
2 title={Mecellem Models: Turkish Models Trained from Scratch and Continually Pre-trained for the Legal Domain},
3 author={Uğur, Özgür and Göksu, Mahmut and Çimen, Mahmut and Yılmaz, Musa and Şavirdi, Esra and Demir, Alp Talha and Güllüce, Rumeysa and Çetin, İclal and Sağbaş, Ömer Can},
4 journal={arXiv preprint arXiv:2601.16018},
5 year={2026},
6 month={January},
7 url={https://arxiv.org/abs/2601.16018},
8 doi={10.48550/arXiv.2601.16018},
9 eprint={2601.16018},
10 archivePrefix={arXiv},
11 primaryClass={cs.CL}
12}
Base Model References
bibtex
1@inproceedings{modernbert2025,
2 title={ModernBERT: A Modern Bidirectional Encoder Transformer},
3 author={Answer.AI and LightOn},
4 booktitle={Proceedings of the 2025 Conference on Language Models},
5 year={2025}
6}
bibtex
1@misc{bge-m3,
2 title={BGE M3-Embedding: Multi-Lingual, Multi-Functionality, Multi-Granularity Text Embeddings Through Self-Knowledge Distillation},
3 author={Chen, Jianlv and Xiao, Shitao and Zhang, Peitian and Luo, Kun and Lian, Defu and Liu, Zheng},
4 year={2024},
5 eprint={2402.03216},
6 archivePrefix={arXiv},
7 primaryClass={cs.CL}
8}