DFT-DEE-THF | Kailos Dashboard

Overview

2 / 3

Phases Complete

Phase 1-2 done, Phase 3 in progress

Optimized Structures

11 pure + 5 CIP (+ 5 excluded)

PES Scans

6 complete, 2 running, 2 early-stage

13/3

Grade Distribution

A: 13 | A-: 1 | B: 2 | C: 0

Pipeline Phase 3 Active

%%{init: {'theme': 'dark', 'themeVariables': {'primaryColor': '#21262d', 'edgeLabelBackground': '#161b22'}}}%% graph LR P1["Phase 1
Monomer Opt+Freq
5/5 DONE"] -->|ZPE, reference energies| P2 P2["Phase 2
Solvation Clusters
16/16 DONE"] -->|Optimized geometries| P3 P3["Phase 3
Desolvation PES
6/10 done"] P2 -->|CIP structures| P2C["Phase 2 CIP
FSI Contact Pairs
5/5 DONE"] style P1 fill:#1a3a1a,stroke:#3fb950,color:#e6edf3 style P2 fill:#1a3a1a,stroke:#3fb950,color:#e6edf3 style P2C fill:#1a3a1a,stroke:#3fb950,color:#e6edf3 style P3 fill:#1a2a3a,stroke:#58a6ff,color:#e6edf3

Publication Descriptors

Confirmed (Phase 1-2)

Binding Energy (dE) ZPE-corrected (dE_ZPE) Enthalpy (dH) Gibbs Free Energy (dG) Temperature Dependence (3T) Entropy Penalty (TdS) NPA Charge Transfer HOMO/LUMO Gap Dipole Moment CIP Binding (FSI-) DDG(DEE-THF) Comparison

In Progress (Phase 3)

Desolvation Barrier (dG_barrier) PES Profile (Li-O distance) TTE Removal Barrier

Planned (Phase 4-6)

RDF / Coordination (AIMD) Diffusion Coefficient Interface Adsorption LED Decomposition

Phase 1: Monomer Properties

Molecule	E (Eh)	ZPE (kcal/mol)	Dipole (D)	HOMO (eV)	LUMO (eV)	Gap (eV)
Li⁺	-7.2897	0.00	0.000	-66.65	-5.30	61.35
DEE	-233.6889	86.23	1.085	-9.53	3.25	12.78
THF	-232.4772	74.03	1.618	-9.53	3.15	12.68
FSI^-	-1351.9269	19.88	0.421	-6.49	7.26	13.75
TTE	-1067.0989	65.89	1.249	-12.22	2.89	15.11

THF dipole (1.62 D) > DEE (1.09 D): stronger electrostatic attraction to Li⁺. TTE has the largest gap (15.11 eV): electrochemical stability.

Phase 2: Solvation Thermodynamics Complete

Pure Solvation Clusters (233K / -40 C)

Cluster	dE	dE_ZPE	dH	dG	TdS	Grade	Notes
Li(DEE)₁	-39.58	-38.11	-38.62	-33.25	-5.37	A	0 imag
Li(DEE)₂	-44.94	-47.09	-45.99	-34.73	-11.26	B	1 imag (-25 cm^-1)
Li(THF)₁	-41.72	-40.28	-40.86	-34.95	-5.91	A	0 imag (reopt)
Li(THF)₂	-75.42	-72.87	-73.17	-59.20	-13.96	A	0 imag (reopt)
Li(THF)₄	-122.15	-117.78	-116.49	-90.57	-25.93	A	0 imag (reopt)

TTE Mixed Clusters (233K)

Cluster	dE	dE_ZPE	dH	dG	TdS	Grade	Notes
Li(THF)₁(TTE)₁	-71.14	-68.95	-69.82	-53.32	-16.50	B	1 imag (-8.5 cm^-1)
Li(THF)₂(TTE)₁	-69.79	-71.41	-69.92	-47.53	-22.39	A	0 imag
Li(THF)₁(TTE)₂	-65.16	-62.37	-62.91	-34.16	-28.75	A-	1 imag (-6.6 cm^-1)
Li(THF)₂(TTE)₂	-29.40	-32.93	-30.85	+3.65	-34.51	A	0 imag, dG > 0
Li(DEE)₂(TTE)₁	-41.09	-41.67	-40.04	-18.51	-21.53	A	0 imag
Li(DEE)₁(TTE)₂	-30.34	-34.53	-32.70	-9.56	-23.14	A	0 imag

FSI^- Contact Ion Pairs (CIP, 233K)

Cluster	dE	dG	Li-O(FSI) (A)	Li-O(Solv) (A)	Grade
Li(FSI)(DEE)₁	-154.08	-136.75	1.892 / 1.897	1.909	A
Li(FSI)(DEE)₂	-171.34	-142.22	1.981 / 1.986	2.006 / 2.007	A
Li(FSI)(THF)₁	-155.62	-137.46	1.898 / 1.886	1.891	A
Li(FSI)(THF)₂	-173.64	-143.93	1.965 / 1.933	1.930 / 1.944	B
Li(FSI)(THF)₃	-190.14	-155.79	--	--	A

DDG Comparison: DEE vs THF (233K)

Category	Pair	dG(DEE)	dG(THF)	DDG	Interpretation
Solvation	n=1	-33.25	-34.95	-1.69	THF slightly stronger
Solvation	n=2	-34.73	-59.20	-24.48	THF much stronger
TTE mixed	n=2, m=1	-18.51	-47.53	-29.02	THF much stronger
TTE mixed	n=1, m=2	-9.56	-34.16	-24.61	THF much stronger
CIP	n=1	-136.75	-137.46	-0.71	Nearly equal (FSI^- dominates)
CIP	n=2	-142.22	-143.93	-1.71	Nearly equal (FSI^- dominates)

Excluded Systems (Steric Failure)

System	dE (kcal/mol)	Reason
Li(DEE)₃	+19.81	Only 1/3 DEE coordinates (steric failure)
Li(DEE)₄	+66.24	Only 2/4 DEE coordinates (steric failure)
Li(THF)₃	-25.83	Only 2/3 THF coordinates
Li(DEE)₁(TTE)₁	+45.85	Fully dissociated (Li-O = 6.6 A)
Li(DEE)₂(TTE)₂	+59.83	Steric failure

dG Binding Energy (233K)

Entropy Penalty (TdS at 233K)

DDG(DEE - THF) at 233K

Phase 3: Desolvation Barriers In Progress

Scan Status

Scan	Reaction	Points	Status	Barrier (kcal/mol)
DEE2-TTE desolvation	Li⁺(DEE)₂(TTE) → Li⁺(DEE)(TTE) + DEE	20/20	COMPLETE	17.01
THF2-TTE desolvation	Li⁺(THF)₂(TTE) → Li⁺(THF)(TTE) + THF	19/20	COMPLETE	6.73
FSI-DEE2 desolvation	Li⁺FSI^-(DEE)₂ → Li⁺FSI^-(DEE) + DEE	20/20	COMPLETE	9.86
FSI-THF2 desolvation	Li⁺FSI^-(THF)₂ → Li⁺FSI^-(THF) + THF	19/20	COMPLETE	5.64
THF4 desolvation	Li⁺(THF)₄ → Li⁺(THF)₃ + THF	20/20	COMPLETE	13.27
DEE4 desolvation	Li⁺(DEE)₄ → Li⁺(DEE)₃ + DEE	18/20	RUNNING	22.08
DEE2-TTE removal	Li⁺(DEE)₂(TTE) → Li⁺(DEE)₂ + TTE	20/20	COMPLETE	6.89
THF2-TTE removal	Li⁺(THF)₂(TTE) → Li⁺(THF)₂ + TTE	20/20	COMPLETE	2.94
DEE1-TTE2 removal	Li⁺(DEE)(TTE)₂ → Li⁺(DEE)(TTE) + TTE	1/20	RUNNING	--
THF1-TTE2 removal	Li⁺(THF)(TTE)₂ → Li⁺(THF)(TTE) + TTE	3/20	RUNNING	0.30

%%{init: {'theme': 'dark'}}%% graph TB subgraph Desolvation["Desolvation Scans"] D1["DEE2-TTE desol
17.01 kcal/mol
COMPLETE"] T1["THF2-TTE desol
6.73 kcal/mol
COMPLETE"] D2["FSI-DEE2 desol
9.86 kcal/mol
COMPLETE"] T2["FSI-THF2 desol
5.64 kcal/mol
COMPLETE"] T3["THF4 desol
13.27 kcal/mol
COMPLETE"] D3["DEE4 desol
22.08 kcal/mol
RUNNING"] end subgraph Removal["TTE Removal Scans"] R1["DEE2-TTE removal
6.89 kcal/mol
COMPLETE"] R2["THF2-TTE removal
2.94 kcal/mol
COMPLETE"] R3["DEE1-TTE2 removal
RUNNING 1/20"] R4["THF1-TTE2 removal
RUNNING 3/20"] end style D1 fill:#1a3a1a,stroke:#3fb950 style T1 fill:#1a3a1a,stroke:#3fb950 style D2 fill:#1a3a1a,stroke:#3fb950 style T2 fill:#1a3a1a,stroke:#3fb950 style T3 fill:#1a3a1a,stroke:#3fb950 style D3 fill:#1a2a3a,stroke:#58a6ff style R1 fill:#1a3a1a,stroke:#3fb950 style R2 fill:#1a3a1a,stroke:#3fb950 style R3 fill:#1a2a3a,stroke:#58a6ff style R4 fill:#1a2a3a,stroke:#58a6ff

PES Profiles: Desolvation (Li-O distance)

Barrier Comparison (kcal/mol)

NPA Charge Analysis

Cluster	Type	Li (Mulliken)	Li (Loewdin)	CT (Mulliken)	CT (Loewdin)	n(O)
Li(DEE)₁	Pure	+0.907	+0.749	0.093	0.251	1
Li(DEE)₂	Pure	+0.616	+0.397	0.384	0.603	2
Li(THF)₁	Pure	+0.928	+0.799	0.072	0.201	1
Li(THF)₂	Pure	+0.878	+0.632	0.122	0.368	2
Li(THF)₄	Pure	+0.779	+0.406	0.221	0.594	4
Li(FSI)(DEE)₁	CIP	+0.829	+0.562	FSI^- dominated		5
Li(FSI)(DEE)₂	CIP	+0.778	+0.349	FSI^- dominated		6

DEE shows larger charge transfer per molecule than THF: DEE is a better electron donor per O atom, but THF compensates with higher coordination number.

Reliability Assessment

Grade Distribution

A True minimum (0 imag)	13
A- Quasi-minimum (< -10 cm^-1)	1
B Small imag (< -30 cm^-1)	2
C Significant imag	0

81% Grade A. All B grades have imaginary frequencies < -25 cm^-1 (quasi-RRHO threshold).

Methodology Validation

Functional	wB97X-D3 (range-separated hybrid + D3)
Basis Set	def2-TZVP (triple-zeta)
Dispersion	Built-in D3 correction
Thermochemistry	Quasi-RRHO (Grimme, B_av)
SCF Convergence	TightSCF (1e-8 Eh)
RI Approximation	RIJCOSX / def2/J

Known Limitations

Gas-phase calculations (no implicit solvent model)
Single conformer per cluster (no conformational averaging)
DEE steric constraint: max 2-coordinate (DEE₃, DEE₄ excluded)
Phase 3 PES: relaxed scan (not IRC), approximate barrier
BSSE not explicitly corrected (mitigated by TZVP basis)

Reoptimization Log

Li(THF)₁	Disp reopt → true minimum	A
Li(THF)₂	Reopt → true minimum	A
Li(THF)₄	Reopt → true minimum (dG shift: -8 kcal/mol)	A
Li(FSI)(THF)₃	Reopt → true minimum (new CIP)	A

Scientific Discussion

1. Solvation Thermodynamics: THF Always Wins

At 233K, THF forms dramatically stronger solvation shells than DEE. For n=2: DDG = -24.5 kcal/mol in THF's favor. The cyclic rigidity of THF allows efficient packing around Li⁺ (up to 4-coordinate), while DEE's linear flexibility causes steric exclusion beyond n=2. This asymmetric coordination capacity is the fundamental structural difference.

2. TTE Effect: Entropy-Driven Destabilization

TTE systematically weakens solvation (dG becomes less negative) through massive entropy penalties. Li(THF)₂(TTE)₂ has dG = +3.65 kcal/mol (thermodynamically unfavorable) despite dH = -30.85 kcal/mol. The TdS penalty scales with TTE count: -16.5 (1 TTE) → -28.8 (2 TTE) → -34.5 kcal/mol (2 TTE + 2 solvent). This confirms TTE's role as a non-coordinating diluent that creates entropy-driven lability in the solvation shell.

3. The Barrier Paradox: Weaker Binding, Higher Barrier?

Preliminary Phase 3 data reveals a counterintuitive trend: DEE desolvation barriers (17.0 kcal/mol) are significantly higher than THF (6.7 kcal/mol), despite DEE having weaker binding. Two hypotheses: (1) DEE's linear geometry creates a conformational trap — the transition state requires an unfavorable geometry that cyclic THF avoids, or (2) the Li-O(TTE) interaction provides a better relay for THF displacement. CIP barriers show a similar but reduced trend (9.9 vs 5.6 kcal/mol), suggesting FSI^- partially compensates.

4. Entropy as the Hidden Variable

Temperature dependence analysis shows dG shifts 8-12 kcal/mol between 298K and 223K for TTE-containing clusters. The implication: at low temperature, entropy penalties decrease, making the TTE-disrupted shells relatively more stable. This means the LHCE design principle (TTE dilution) becomes less effective at low T. The practical consequence: DEE's inherently weaker binding (less entropy penalty at low T) may translate to easier desolvation kinetics despite the paradoxical PES barrier.

Progress 72%

Phase 1: Monomer Optimization

5/5 (100%)

Phase 2: Solvation Clusters

16/16 (100%) + 5 CIP

Phase 3: Desolvation PES Scans

6/10 complete (60%)

Currently Running

Calculation	PID	Progress	Notes
DEE2_TTE1 remove DEE (FIX v2)	391599	Step 1/20	Model Hessian, conservative step. Fixed .carthess bug.
THF2_TTE1 remove THF (restart)	391659	Step 1/14 (=17/30)	Restart from step 17, increased maxcore 8000.

Remaining Work

Task	Priority	Dependency	Est. Time
Complete DEE2_TTE1 scan (20 steps)	HIGH	Running now	~24-48h
Complete THF2_TTE1 scan (14 steps)	HIGH	Running now	~18-36h
DEE4 desolvation (2 more steps)	MED	After current scans	~4h
DEE1_TTE2 removal (19 more steps)	MED	After current scans	~24h
THF1_TTE2 removal (17 more steps)	MED	After current scans	~24h
Extract dG_barrier(T) from PES	LOW	All scans complete	~2h (script)

%%{init: {'theme': 'dark'}}%% gantt title Phase 3 Timeline dateFormat YYYY-MM-DD axisFormat %m/%d section Desolvation DEE2-TTE desol :done, d1, 2026-03-15, 2026-03-20 THF2-TTE desol :done, d2, 2026-03-15, 2026-03-22 FSI-DEE2 desol :done, d3, 2026-03-18, 2026-03-25 FSI-THF2 desol :done, d4, 2026-03-18, 2026-03-24 THF4 desol :done, d5, 2026-03-20, 2026-03-28 DEE4 desol :active, d6, 2026-03-20, 2026-04-08 section TTE Removal DEE2-TTE removal :done, r1, 2026-03-22, 2026-03-30 THF2-TTE removal :done, r2, 2026-03-22, 2026-04-01 DEE1-TTE2 removal :active, r3, 2026-04-05, 2026-04-08 THF1-TTE2 removal :active, r4, 2026-04-05, 2026-04-08 section Analysis Barrier extraction :crit, a1, 2026-04-09, 2026-04-10 Publication figures :crit, a2, 2026-04-10, 2026-04-12

DFT-DEE-THF Project | Kailos Dashboard v3.0 | Generated 2026-04-05 13:55 KST
wB97X-D3/def2-TZVP | ORCA 6.1.0 | Quasi-RRHO Thermochemistry

DFT-DEE-THF: Cyclic vs Linear Ether in LiFSI/TTE LHCE

Overview

Pipeline Phase 3 Active

Publication Descriptors

Confirmed (Phase 1-2)

In Progress (Phase 3)

Planned (Phase 4-6)

Phase 1: Monomer Properties

Phase 2: Solvation Thermodynamics Complete

Pure Solvation Clusters (233K / -40 C)

TTE Mixed Clusters (233K)

FSI- Contact Ion Pairs (CIP, 233K)

DDG Comparison: DEE vs THF (233K)

Excluded Systems (Steric Failure)

dG Binding Energy (233K)

Entropy Penalty (TdS at 233K)

DDG(DEE - THF) at 233K

Phase 3: Desolvation Barriers In Progress

Scan Status

PES Profiles: Desolvation (Li-O distance)

Barrier Comparison (kcal/mol)

NPA Charge Analysis

Reliability Assessment

Grade Distribution

Methodology Validation

Known Limitations

Reoptimization Log

Scientific Discussion

1. Solvation Thermodynamics: THF Always Wins

2. TTE Effect: Entropy-Driven Destabilization

3. The Barrier Paradox: Weaker Binding, Higher Barrier?

4. Entropy as the Hidden Variable

Progress 72%

Phase 1: Monomer Optimization

Phase 2: Solvation Clusters

Phase 3: Desolvation PES Scans

Currently Running

Remaining Work

FSI^- Contact Ion Pairs (CIP, 233K)